Fix: Extend VTS to support multiple display if available.

This fixes I65d7fae47d486121b047a7c888db11c4842b4640

Fix:
Extend writers and readers to be unique per display at all stages
including teardown.
Fix an unexplicit use of DisplayWrapper

Bug: b/391347760, b/355482219
Test: atest VtsHalGraphicsComposer3_TargetTest on CF, AL and Comet
Flag: TEST_ONLY
Change-Id: I93694c65fd6a55fd95080afc5138ea060ab85160