Support passing ClientConfiguration to web identity credentials provider.

[teo-tsirpanis]

Issue #, if available:

Description of changes: This PR updates the constructor of STSAssumeRoleWebIdentityCredentialsProvider to accept an optional ClientConfiguration parameter.

Also the provider no longer tries to determine itself the region to use and instead always defers to the region specified in the config. This shouldn't have any practical effect since the default constructor of ClientConfiguration has a similar (and slightly more extensive) logic either way.

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• Did a review by yourself.
• Added proper tests to cover this PR. (If tests are not applicable, explain.)
• Checked if this PR is a breaking (APIs have been changed) change.
• Checked if this PR will not introduce cross-platform inconsistent behavior.
• Checked if this PR would require a ReadMe/Wiki update.

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[sbera87]

looks ok to me otherwise. Now region needs to be passed through the config, there is no fallback

[teo-tsirpanis]

Now region needs to be passed through the config, there is no fallback

@sbera87 what do you mean? I don't understand.

[SergeyRyabinin]

I'm really sorry for a a big delay in the handling of this PR.
I've been running a CI check and just noticed that

it is actually changing the default constructor to make an IMDS call (to resolve a region, not always though, but still...), this is a significant change of existing behavior.

could you please change it to

STSAssumeRoleWebIdentityCredentialsProvider(Aws::Client::ClientConfiguration config = {Aws::Client::ClientConfigurationInitValues{true}});

so IMDS won't be auto-enabled?

We should be able to merge the PR shortly after this.
Thank you!

[teo-tsirpanis]

Done.

[SergeyRyabinin]

looks ok to me otherwise. Now region needs to be passed through the config, there is no fallback

The client config will fallback to the us-east-1 if not set:

aws-sdk-cpp/src/aws-cpp-sdk-core/source/client/ClientConfiguration.cpp

Line 266 in f8efa6a

region = Aws::String(Aws::Region::US_EAST_1);

[SergeyRyabinin]

Sorry, it has failed the build.

In file included from /tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/source/auth/AWSCredentialsProviderChain.cpp:7:0,
                 from src/aws-cpp-sdk-core/ub_core.cpp:3:
/tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/include/aws/core/auth/STSCredentialsProvider.h:28:147: error: no matching function for call to 'Aws::Client::ClientConfigurationInitValues::ClientConfigurationInitValues(<brace-enclosed initializer list>)'
             STSAssumeRoleWebIdentityCredentialsProvider(Aws::Client::ClientConfiguration config = {Aws::Client::ClientConfigurationInitValues{true}});
                                                                                                                                                   ^
In file included from /tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/include/aws/core/internal/AWSHttpResourceClient.h:11:0,
                 from /tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/include/aws/core/auth/AWSCredentialsProvider.h:17,
                 from /tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/source/auth/AWSCredentialsProvider.cpp:7,
                 from src/aws-cpp-sdk-core/ub_core.cpp:2:
/tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/include/aws/core/client/ClientConfiguration.h:67:16: note: candidate: constexpr Aws::Client::ClientConfigurationInitValues::ClientConfigurationInitValues()
         struct ClientConfigurationInitValues {
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/include/aws/core/client/ClientConfiguration.h:67:16: note:   candidate expects 0 arguments, 1 provided
/tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/include/aws/core/client/ClientConfiguration.h:67:16: note: candidate: constexpr Aws::Client::ClientConfigurationInitValues::ClientConfigurationInitValues(const Aws::Client::ClientConfigurationInitValues&)
/tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/include/aws/core/client/ClientConfiguration.h:67:16: note:   no known conversion for argument 1 from 'bool' to 'const Aws::Client::ClientConfigurationInitValues&'
/tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/include/aws/core/client/ClientConfiguration.h:67:16: note: candidate: constexpr Aws::Client::ClientConfigurationInitValues::ClientConfigurationInitValues(Aws::Client::ClientConfigurationInitValues&&)
/tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/include/aws/core/client/ClientConfiguration.h:67:16: note:   no known conversion for argument 1 from 'bool' to 'Aws::Client::ClientConfigurationInitValues&&'
In file included from /tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/source/auth/AWSCredentialsProviderChain.cpp:7:0,
                 from src/aws-cpp-sdk-core/ub_core.cpp:3:
/tmp/aws-sdk-cpp/src/aws-cpp-sdk-core/include/aws/core/auth/STSCredentialsProvider.h:28:148: error: could not convert '{<expression error>}' from '<brace-enclosed initializer list>' to 'Aws::Client::ClientConfiguration'
             STSAssumeRoleWebIdentityCredentialsProvider(Aws::Client::ClientConfiguration config = {Aws::Client::ClientConfigurationInitValues{true}});

Let me handle the update for this PR.