Update to 5.1.0_r5

Change-Id: I46b035241031b2ca0f3cab63545a25ef9b1ddd8f

default.xml

@@ -15,7 +15,7 @@
            review="gerrit.omnirom.org"
            fetch="https://github.com/omnirom" />
 
-  <default revision="refs/tags/android-5.1.0_r3"
+  <default revision="refs/tags/android-5.1.0_r5"
            remote="aosp"
            sync-c="true"
            sync-j="4" />