Merge "Add filegroup_test.go to sources" am: eaab87405c am: 51f92dc397

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2470484

Change-Id: I57930f7529760d0075ab820865a8b7f79385be91
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>