AudioPolicy: Replace ALOG with nullptr check before adding values to vector

Bug: 277299684
Test: ./audiopolicy_fuzzer clusterfuzz-testcase-minimized-audiopolicy_fuzzer-4740706102804480
Test: ./audiopolicy_fuzzer clusterfuzz-testcase-minimized-audiopolicy_fuzzer-4913502336647168
Change-Id: Ie76f32d2f67beb22f3a92d14ebb31a49c1e574d6
1 file changed