[sepolicy] allow system_server to ioctl INCFS_IOC_GET_LAST_READ_ERROR

Solves the denial message like:

04-30 03:54:46.972 21944 21944 I Binder:21944_17: type=1400 audit(0.0:502): avc: denied { ioctl } for path=2F646174612F696E6372656D656E74616C2F4D545F646174615F6170705F766D646C3133352F6D6F756E742F2E70656E64696E675F7265616473202864656C6574656429 dev="incremental-fs" ino=2 ioctlcmd=0x6727 scontext=u:r:system_server:s0 tcontext=u:object_r:incremental_control_file:s0 tclass=file permissive=1

BUG: 184844615
Test: manual
Change-Id: I3ef32613de348bca1d58cddf4ec1296d4828b51a
2 files changed