Fix various typos in ART's comments and string literals.

Change-Id: I85d628055b1a61647a77fef730c9631c234e22a2
diff --git a/runtime/common_runtime_test.cc b/runtime/common_runtime_test.cc
index e89c5af..3df9101 100644
--- a/runtime/common_runtime_test.cc
+++ b/runtime/common_runtime_test.cc
@@ -232,7 +232,7 @@
   }
 
   if (founddir.empty()) {
-    ADD_FAILURE() << "Can not find Android tools directory.";
+    ADD_FAILURE() << "Cannot find Android tools directory.";
   }
   return founddir;
 }