Change IsMethodTracingActive to GetMethodTracingMode for art.

This allows traceview to tell whether sampling or just normal
method profiling is enabled.

Bug: 9968521

Change-Id: I518a1888a90bc50568fe56bf708d801027ac98d7
(cherry picked from commit 64caa7dcf46ed6139b766dbe77fbd7353899417f)
3 files changed