MAP: Close Email ContentProvider while closing service or disconnect

Usecase:
1) Create MAP Session for Email MAS Instance and register MNS.
2) Deregister MNS from remote side.
3) Push Email message to outbox.

Issue:
Push Message fails with response OBEX_HTTP_BAD_REQUEST

Root Cause:
ContentProviderClient for Email was getting closed and released on
deregisering MNS.

Fix:
Close ContentProviderClient for email while closing down service
or disconnection.

Change-Id: I75ae40668425cb32e36d8d33745295da379b31fa
CRs-Fixed: 2326663
1 file changed