Read by UUID for PTS tests (2/5)

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

Bug: 35150313
Test: sl4a GattReadTest.byUuid
Change-Id: I6ec848eac1ecfbd1a4ec2bc968faff8a082d9c79
(cherry picked from commit 5fc203008497b071dc583450a53c93e11dd561ff)
2 files changed