Fix clang-tidy warnings in mediaresourcemanager.

* Add explicit keyword to conversion constructors.
Bug: 28341362
* Use const reference type for read-only parameters.
Bug: 30407689
Test: build with WITH_TIDY=1

Change-Id: I9aac64b379ddb77a9abb4b03a6648f38e2a756ab
diff --git a/services/mediaresourcemanager/test/ResourceManagerService_test.cpp b/services/mediaresourcemanager/test/ResourceManagerService_test.cpp
index 62b7711..ed0b0ef 100644
--- a/services/mediaresourcemanager/test/ResourceManagerService_test.cpp
+++ b/services/mediaresourcemanager/test/ResourceManagerService_test.cpp
@@ -29,7 +29,7 @@
 
 namespace android {
 
-static int64_t getId(sp<IResourceManagerClient> client) {
+static int64_t getId(const sp<IResourceManagerClient>& client) {
     return (int64_t) client.get();
 }