ActivityManager: add option to allow OpenGL trace.

This patch adds an option to enable tracing of OpenGL functions.
OpenGL tracing can be enabled by passing "--opengl-trace" option
to am start.  This option requires either a device in debug mode,
or that the application itself has debug permission set.

Change-Id: I77788bfe97c9108943b1f947ce81afe8293d78a0