Fix null pointer exceptions in NetworkPolicyEditor

This upload fixes a null pointer exception issue.
After this fix the modified methods return
their corresponding default values instead of null.

Change-Id: Idb94f8b808b8dd18be5e3fc92cc5560ce0f81c4f
Bluetooth: Set alias name only through Rename option

Set the alias name only when user is trying to change the
name using the Rename option of paired device.

CRs-Fixed: 539420
Change-Id: I415b6a962d8e7884b67d37b94c04df19e2c23012
Bluetooth: Don't set a null alias before unpairing

* This causes the unpair action to throw a null pointer exception and
  bring down the Settings app. Don't do this.

Change-Id: I0c60437f5ea934385a037a464743e24c9d341aca
Build V32