Frameworks/base: Add tracing system properties

Add system properties to support zygote-started method tracing.
These are needed as the limit on system properties does not allow
the reuse of the runtime extra options system property.

Bug: 21760614

(cherry picked from commit 98f406f6f31660d0f5ee32113ffadc720b426dc6)

Change-Id: I3785cc5715acadbee81ef7b45081ed780f1351d3
1 file changed