Fix RTL issue in Trusted Credentail page

Two changes are required to fix the issue.
1. The width of the textview needed to be wrap_content in order
   to resolve the random issue. I guess it is a framework bug, but
   anyway the UI looks the same after the change
2. textAlignment="viewStart" is needed to make the textview RTL
3. Clean up: Change the RelativeLayout to a vertical LinearLayout

Bug: 28757193
Change-Id: I1142d4dd31eb86b80f5a2316c1c7825df287b609