Skip telecom focus test for voip app

Skip the test of telecom lock foucs for transacational voip app
since car audio focus does not support this.

Bug: 376361440
Flag: EXEMPT bugfix
Test: atest android.telecom.cts.cuj.app.integration.SingleCallingTest
Change-Id: I1d01eaaa1821f48e2783248da6894add86c810cd