ART: Remove "explicit" annotation

Remove unnecessary annotation.

Bug: 32619234
Test: m
Change-Id: I8bbef5e3b4b8d3f5ddeaece08fe614b9eeae6f2c
diff --git a/runtime/common_runtime_test.h b/runtime/common_runtime_test.h
index 827e85e..17e3729 100644
--- a/runtime/common_runtime_test.h
+++ b/runtime/common_runtime_test.h
@@ -52,7 +52,7 @@
 
   ScratchFile(const ScratchFile& other, const char* suffix);
 
-  explicit ScratchFile(ScratchFile&& other);
+  ScratchFile(ScratchFile&& other);
 
   ScratchFile& operator=(ScratchFile&& other);