Upgrade drm_hwcomposer to 75855a6ab877011a2e26ae95da7ddf06dd3a04b2 am: 21a455e841

Original change: https://android-review.googlesource.com/c/platform/external/drm_hwcomposer/+/3498135

Change-Id: I397ec533683fc283d0125a0905e3e74176185745
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>