Allow installd to move around private app data.

Add rules that allow installd to move private app data between
internal and expanded storage devices.  For now we'll be reusing
the "cp" binary using android_fork_execvp(), so grant access to
devpts.

avc: denied { read write } for name="14" dev="devpts" ino=17 scontext=u:r:installd:s0 tcontext=u:object_r:devpts:s0 tclass=chr_file permissive=1
avc: denied { open } for path="/dev/pts/14" dev="devpts" ino=17 scontext=u:r:installd:s0 tcontext=u:object_r:devpts:s0 tclass=chr_file permissive=1

avc: denied { read } for name="com.android.opengl.shaders_cache" dev="mmcblk0p16" ino=114672 scontext=u:r:installd:s0 tcontext=u:object_r:app_data_file:s0:c512,c768 tclass=file permissive=1
avc: denied { open } for path="/data/data/com.example.playground/code_cache/com.android.opengl.shaders_cache" dev="mmcblk0p16" ino=114672 scontext=u:r:installd:s0 tcontext=u:object_r:app_data_file:s0:c512,c768 tclass=file permissive=1
avc: denied { create } for name="com.android.opengl.shaders_cache" scontext=u:r:installd:s0 tcontext=u:object_r:app_data_file:s0 tclass=file permissive=1
avc: denied { read write open } for path="/mnt/expand/57f8f4bc-abf4-655f-bf67-946fc0f9f25b/user/0/com.example.playground/code_cache/com.android.opengl.shaders_cache" dev="dm-0" ino=64518 scontext=u:r:installd:s0 tcontext=u:object_r:app_data_file:s0 tclass=file permissive=1

Bug: 19993667
Change-Id: I5188e660c8b5e97eab8f0c74147499ec688f3f19