ART: Refactor HandleUnexpectedSignalCommon

Avoid the std::ostringstream. Instead use a lambda and immediately
use std::cerr when asked to dump there, eventually.

Also refactor the signature to make it more explicit what the function
will handle and where it would dump to.

Test: m test-art-host
Change-Id: I2be5497d4f9957127243879113372d9aa1535d82
diff --git a/runtime/runtime_android.cc b/runtime/runtime_android.cc
index 495296c..4bd3b3a 100644
--- a/runtime/runtime_android.cc
+++ b/runtime/runtime_android.cc
@@ -27,7 +27,11 @@
 struct sigaction old_action;
 
 void HandleUnexpectedSignalAndroid(int signal_number, siginfo_t* info, void* raw_context) {
-  HandleUnexpectedSignalCommon(signal_number, info, raw_context, /* running_on_linux */ false);
+  HandleUnexpectedSignalCommon(signal_number,
+                               info,
+                               raw_context,
+                               /* handle_timeout_signal */ false,
+                               /* dump_on_stderr */ false);
 
   // Run the old signal handler.
   old_action.sa_sigaction(signal_number, info, raw_context);