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

* Add explicit to conversion constructors/operators
* Use NOLINT or NOLINTNEXTLINE to suppress warnings on intended converters

Bug: 28341362
Test: make with WITH_TIDY=1 DEFAULT_GLOBAL_TIDY_CHECKS=-*,google-explicit-constructor
Change-Id: I3631041531e3fb5cbcee246a7e7bb94fb06aa60b
diff --git a/libs/vr/libpdx/serialization_tests.cpp b/libs/vr/libpdx/serialization_tests.cpp
index 5ad1047..ee800f6 100644
--- a/libs/vr/libpdx/serialization_tests.cpp
+++ b/libs/vr/libpdx/serialization_tests.cpp
@@ -70,7 +70,7 @@
   FileHandleType fd;
 
   TestTemplateType() {}
-  TestTemplateType(FileHandleType fd) : fd(std::move(fd)) {}
+  explicit TestTemplateType(FileHandleType fd) : fd(std::move(fd)) {}
 
   bool operator==(const TestTemplateType& other) const {
     return fd.Get() == other.fd.Get();