isolated_app: add mmaps

Kernel commit 3ba4bf5f1e2c ("selinux: add a map permission check for mmap")
added a map permission check on mmap so that we can
distinguish memory mapped access (since it has different implications
for revocation). system/sepolicy commit
4397f082 introduced the permission to
Android and updated common macros. Since then, we've been adding more
mmap support where it was accidentally omitted.

Add the ability for isolated_apps to mmap() app data files. There's no
reason why this should be blocked. Also fixup sdcard access which has
similar problems.

Bug: 118760652
Bug: https://crbug.com/892014
Test: policy compiles.
Change-Id: I3823f313103c9dcedf3b21d081a22f8fbb271c02