ART: Set default prune counter to 10

By default, prune cache at boot after ten failed boots.

Bug: 19983101
Change-Id: Ib88f807e0082d71292c14c7af38e02cca5a5602c
diff --git a/runtime/runtime_options.def b/runtime/runtime_options.def
index 1f273cf..339f925 100644
--- a/runtime/runtime_options.def
+++ b/runtime/runtime_options.def
@@ -119,7 +119,7 @@
                                                                           // We don't call abort(3) by default; see
                                                                           // Runtime::Abort.
 RUNTIME_OPTIONS_KEY (void (*)(),          HookAbort,                      nullptr)
-RUNTIME_OPTIONS_KEY (unsigned int,        ZygoteMaxFailedBoots,           1)
+RUNTIME_OPTIONS_KEY (unsigned int,        ZygoteMaxFailedBoots,           10)
 RUNTIME_OPTIONS_KEY (Unit,                NoDexFileFallback)
 
 #undef RUNTIME_OPTIONS_KEY