Cache the inference service-uid when connected and reuse in

LocalServices

- This is not fixing the bug in questions, but removing the extra
 `getIsolatedOwner` call that was being made for all isolated uids,
 which was increasing the error log rate significantly.

Bug: 286903116
Test: atest android.ondeviceintelligence.cts.OnDeviceIntelligenceManagerTest#inferenceServiceShouldReturnParentPackageName
Change-Id: I63e94b567f5fe1f3711e7eaa79298b88d6ef9e58