Read by UUID for PTS tests (1/5)

Add a hidden api for reading characteristic by UUID for PTS.

Bug: 35150313
Test: sl4a GattReadTest.byUuid
Change-Id: Ice4076d99e4694d20374ba0fdcae74d5ae841147
(cherry picked from commit de74891d1c603326691678ec301c80b4525bc4ef)
2 files changed