Add enable_profile_use property

Bug: http://b/65598278

This property defaults to 'true' and setting it to false skips profile
use.  This escape hatch lets us disable PGO for a module without
completely removing the 'pgo' property.  Additionally, this also helps
selectively disabling PGO for some architectures, if desired.

Test: Test that -fprofile-use is not added for a test module if
'enable_profile_use: false' is set.

Change-Id: Ifcf1a48c194bc86efd88a529cc2d66a47b7ab080