Make Get/SetLocalVariables not pause jit.

We were unnecessarily pausing the jit when retrieving or setting local
variables. This could cause deadlocks in some situations.

Test: ./test.py --host -j50
Test: ./art/tools/run-libjdwp-tests.sh --mode=host
Test: see b/111131691

Bug: 111131691
Change-Id: If681b52a2dbabc118a252436e5083f99e79b3ddd