* tests/GoTest.sh: Fix flags.Parse location to work on new go SDKs.
Calling flags.Parse() within init() races with other packages which register
flags in their init(), and in particular with the testing package itself. It is
more reliable to call flags.Parse() from a TestMain implementation.
See https://github.com/golang/go/issues/31859,
https://github.com/golang/go/issues/33869.
* .github: Enable build-go action in build.yaml workflow.
It errors with "Fatal error: Uncaught exception 'InvalidArgumentException' with message 'bad number for type byte.. in /home/runner/work/flatbuffers/flatbuffers/php/ByteBuffer.php:490" which I can't reproduce locally, and trying to fix it on CI runs into PHP's insane handling of numbers vs strings.
Android build was dated, using the Android.mk approach. Current
project configuration on Android encourages the usage of CMake, so we
are updating the android project as an example on how to use either the
Java/Kotlin generate code or the native C++ one.
