docs: Added protection level to permissions

All permissions that are suitable for use by third-party apps and
aren't deprecated now contain a paragraph in their descriptions that
lists the protection level for a given permission, such as:

Protection level: signature|privileged

Test: make ds-docs
Bug: 137260540
Change-Id: I45eada81bf4aa83480ff2e701a9e0e9932b66b88
1 file changed