Update isSameApp check

Only check uid, without a sandbox sdk exception

This small change involves a major test change since we previously
too permissive in our test setup

Test: NotificationManagerServiceTest
Test: HSUM NotificationManagerServiceTest
Test: SdkSandboxRestrictionsTest
Bug: 396667508
Fixes: 317957802
Flag: EXEMPT bug fix

Change-Id: I2be1537803a83cf44cc605f2850a3bb705b9bf32