Fix/suppress libs/gui google-explicit-constructor warnings

* Add explicit to conversion constructors/operators

Bug: 28341362
Test: make with WITH_TIDY=1 DEFAULT_GLOBAL_TIDY_CHECKS=-*,google-explicit-constructor
Change-Id: I76384db26fac6da2de3dbb9092c26c4979324948
diff --git a/libs/gui/include/gui/BufferQueueConsumer.h b/libs/gui/include/gui/BufferQueueConsumer.h
index d108120..aa13c0c 100644
--- a/libs/gui/include/gui/BufferQueueConsumer.h
+++ b/libs/gui/include/gui/BufferQueueConsumer.h
@@ -31,7 +31,7 @@
 class BufferQueueConsumer : public BnGraphicBufferConsumer {
 
 public:
-    BufferQueueConsumer(const sp<BufferQueueCore>& core);
+    explicit BufferQueueConsumer(const sp<BufferQueueCore>& core);
     ~BufferQueueConsumer() override;
 
     // acquireBuffer attempts to acquire ownership of the next pending buffer in