Enable clang-tidy in oboeservice.

Warnings and errors generated by clang-tidy are eliminated by this CL.

Bug: 186572209
Test: make
Test: atest AAudioTests
Change-Id: I3296193bac18fee499f39314ac32a5750a385855
diff --git a/services/oboeservice/AAudioMixer.cpp b/services/oboeservice/AAudioMixer.cpp
index ad4b830..6890985 100644
--- a/services/oboeservice/AAudioMixer.cpp
+++ b/services/oboeservice/AAudioMixer.cpp
@@ -45,7 +45,8 @@
     memset(mOutputBuffer.get(), 0, mBufferSizeInBytes);
 }
 
-int32_t AAudioMixer::mix(int streamIndex, std::shared_ptr<FifoBuffer> fifo, bool allowUnderflow) {
+int32_t AAudioMixer::mix(
+        int streamIndex, const std::shared_ptr<FifoBuffer>& fifo, bool allowUnderflow) {
     WrappingBuffer wrappingBuffer;
     float *destination = mOutputBuffer.get();