Add 'profileable' application manifest tag

Bug: 117841084
Test: atest CtsAtraceHostTestCases:AtraceHostTest

Allow apps to opt-in to important profiling features (systrace, binder
tracing), without requiring debuggable=true. Debuggable has
significant performance overhead, and is undesirable for profiling.

Profileable is set to true when debuggable is true.

Change-Id: I16aaa7bc60dee4b1b262e169ac285759d57d8198