Sepolicy for qemu.sf.back_camera_caps and qemu.sf.front_camera_caps

avc: denied { read } for name="u:object_r:default_prop:s0" dev="tmpfs"
ino=1226 scontext=u:r:hal_camera_default:s0
tcontext=u:object_r:default_prop:s0 tclass=file permissive=0
...
E libc    : Access denied finding property "qemu.sf.back_camera_caps"
...
E libc    : Access denied finding property "qemu.sf.front_camera_caps"

These props are empty and non-functional. Label them to resolve denials.

Bug: 129497117
Test: boot cuttlefish without above denials
Change-Id: I729ced96b7da6e41bfdcb741010a99f827b8a742
Merged-In: I729ced96b7da6e41bfdcb741010a99f827b8a742
(cherry picked from commit 16fc7d0cc4fd1283abe06f0275d077c117e097d0)