Move sysfs_writable to emulator specific policy

This type is never used in core policy, only by emulators.
Move the definition of this type to where it's used.

Fix a bug where search acess wasn't allowed to the sysfs_writable
files.

Bug: 28221393
Change-Id: Iba853a38241a2360812873fe1a2ace47a93c1eb0
2 files changed