Fix build with extra-cmake-modules since commit 7574022825804db2274bba992d6fc4a4817c1536
commits ee5b036c1df4776a258c0d8067fd2eaf18875829 and
7574022825804db2274bba992d6fc4a4817c1536 changed PULSEAUDIO_LIBRARY and
PULSEAUDIO_MAINLOOP_LIBRARY into PulseAudio_LIBRARIES and
PulseAudio_MAINLOOP_LIBRARY.
BUG: 386659