Fix crash when MultipathPolicyTracker cannot get IMSI

Catch the exception when cannot get IMSI to fix races that
network establish/tear down is not in-sync with SIM.
If this happens, this will be automatically recovered when
the next onCapabilitiesChanged event fires.

Test: FrameworksNetTests
Fix: 212399727
Change-Id: I3877806c0f98d8e7e3a77df75738b1799e4b68d3
1 file changed