composer: remove IComposer.dumpDebugInfo

aidl already have a dump funciton, so there is no need to
expose a custom dumpDebugInfo from IComposer.

Bug: 220171623
Test: atest VtsHalGraphicsComposer3_TargetTest
Test: adb shell dumpsys SurfaceFlinger
Test: adb shell dumpsys android.hardware.graphics.composer3.IComposer/default
Change-Id: I5036193c06ba9fdd8aa5f79cd756541d9edc146c