DO NOT MERGE Remove SUBSCRIBED_FEEDS permissions from framework

b/20220885

Instead, move it to GSF:
ag/700092

SUBSCRIBED_FEEDS_READ/WRITE permissions guard the Content Provider
that stores sync feeds for 1p apps (Gmail, Claendar, etc).
The sync feeds are used for delivering and processing
GCM tickle-to-sync messages.

These permissions should not be used by 3rd parties but
if they were, this change will break them.

I don't know the reason these were not in GSF and 'signature'
to begin with. If someone does, please, comment.

Change-Id: I6c4e4c774fea12c7fe7082477c210ad75f007c66