Support waiting for surfaceflinger service to stop before test starts

Bug: 168787663
Bug: 177752568
Test: atest VtsHalGraphicsComposerV2_1TargetTest \
  VtsHalGraphicsComposerV2_2TargetTest \
  VtsHalGraphicsComposerV2_3TargetTest
Change-Id: I1219b8446ca3ac3d22f3fd6ab72cd8a214f55545
(cherry picked from commit e25724e4119c99c78889c8444fee66a79f674857)
8 files changed