[vts] Fix VTS batched-command tests

Fix VTS tests per comments in b/304976052.
Removing redundant tests, as existing CreateLayer, DestroyLayer,
 CreateLayer_BadDisplay and  DestroyLayer_BadDisplay
already provide the needed coverage.

Bug: 304976052
Test: atest VtsHalGraphicsComposer3_TargetTest
      atest PerInstance/GraphicsComposerAidlBatchedCommandTest
Change-Id: I34cb6a69aad6d8f86772a82833b8f15e465fe8d3