add execmod to various app domains

NDK r8c and below induced text relocations into every NDK
compiled shared library. (https://code.google.com/p/android/issues/detail?id=23203).
For compatibility, we need to support shared libraries with text relocations
in them.

Addresses the following error / denial:

  06-02 13:28:59.495  3634  3634 W linker  : libCore.so has text relocations. This is wasting memory and prevents security hardening. Please fix.
  <4>[   57.430677] type=1400 audit(1401740939.756:13): avc: denied { execmod } for pid=3634 comm=".playandlearnhd" path="/data/app-lib/com.adobe.air-2/libCore.so" dev="mmcblk0p28" ino=32745 scontext=u:r:untrusted_app:s0 tcontext=u:object_r:system_data_file:s0 tclass=file

Steps to reproduce:
1) Install Adobe AIR (https://play.google.com/store/apps/details?id=com.adobe.air)
2) Install PBS Parents Play & Learn (https://play.google.com/store/apps/details?id=air.org.pbskids.playandlearnhd)
3) Attempt to run Play & Learn app

Expected:
  App runs

Actual:
  App crashes with error above.

Bug: 15388851
Change-Id: I88bfd72b2abf2407803da0209d2313c8210c6663