docs(sample): Add sample for native image support in Bigtable

[mpeddada1]

This PR copies over the sample for native image support in Bigtable from the old native image support repo.

Some things to note:

1. This PR slightly modifies the sample code to be more test-friendly.
2. It also adds an integration test that can be run as a native image.

Calling mvn package -Pnative in the native-image-sample directory builds the native image for the application and calling mvn test -Pnative runs the test as a native image.

For more information: https://graalvm.github.io/native-build-tools/latest/maven-plugin.html#configuration

[generated-files-bot]

Warning: This pull request is touching the following templated files:

• samples/pom.xml

[snippet-bot]

Here is the summary of changes.

You are about to add 1 region tag.

• samples/native-image-sample/pom.xml:26, tag bigtable_install_with_bom

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[mpeddada1]

The failing GraalVM test is due to no tests being run with the native profile in the emulator module. This is a known issue with the native-maven-plugin, which fails with the following message: Execution test-native of goal org.graalvm.buildtools:native-maven-plugin:0.9.9:test failed: Test configuration file wasn't found.

[mpeddada1]

Thanks for the review @lesv!