Add systrace tag for system property

Introduce a new systrace tag, TRACE_TAG_SYSPROP, for use with
system property.

Bug: 147275573
Test: build
Change-Id: I6f85f3f52f6580bab4ff43fc1dc0e87c689b054e
Merged-In: I6f85f3f52f6580bab4ff43fc1dc0e87c689b054e
(cherry picked from commit 573fc58bad9b49f1e04d01d9e29e5c4a9c32e023)
1 file changed