Revert layer proto format back to proto2

Perfetto doesn't support proto3, hence reverted to proto2.

This reverts commit dcc0bab76dbf3156f18e4dd2697aa7220ad7a8e0

Bug: b/284424784
Test: atest libsurfaceflinger_unittest && atest transactiontrace_testsuite
Change-Id: Ibfc5442c18a3431098eefc53a023f6e66afc7c26
2 files changed