Modified calendar read/write permissions strings per Bug 5008627 Scrub...

Modified calendar read/write permissions strings per Bug 5008627 Scrub calendar permission text for ICS to make it more clear / scary.

Change-Id: I2ea64582670b228d9c816796449d25d770a681cd

Update Calendar permissions strings
Edit based of review: shorten and remove comma.
Bug 5008627

Update Calendar permissions strings
Edit to include mention of access to confidential info.
Bug 5008627

Minor edit to line length.