Default to use mobile network to place self-managed call when the phone

account handle is not permitted to place a call.

Currently, malicious can call TelecomManager#placeCall with a possible
package name to read information of phone account handles. Fallback to
place the self-managed call on mobile network to avoid this kind of
disclosing.

Bug: 191768014
Test: Manually test using debug app
Change-Id: Iab5301d528aa4968874390cce17eb0e5aa599072