Fixed crash when LPA is not available

The embedded subscription result could be null when LPA is not
available on AOSP devices.

Bug: 271349925
Test: v2/android-aosp-tests/device-boot-health-check-extra on aosp_panther-userdebug
Test: Basic phone functionality tests
Merged-In: I3a7cbcdadf30660b73611d13e1fdd8d2cc781f01
Change-Id: I3a7cbcdadf30660b73611d13e1fdd8d2cc781f01