envsetup: repolastsync

Prints date and time of last repo sync. Example:
Last repo sync: 11 Jun 2015, 21:54:59 CDT / 12 Jun 2015, 02:54:59 UTC

Change-Id: I4280b500e58237479194ad2e230ed7466db87755
diff --git a/envsetup.sh b/envsetup.sh
index 6eb9734..57f3d5c 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -29,6 +29,7 @@
 - mka:      Builds using SCHED_BATCH on all processors
 - mkap:     Builds the module(s) using mka and pushes them to the device.
 - cmka:     Cleans and builds using mka.
+- repolastsync: Prints date and time of last repo sync.
 - reposync: Parallel repo sync using ionice and SCHED_BATCH
 - repopick: Utility to fetch changes from Gerrit.
 - installboot: Installs a boot.img to the connected device.
@@ -2115,6 +2116,13 @@
     fi
 }
 
+function repolastsync() {
+    RLSPATH="$ANDROID_BUILD_TOP/.repo/.repo_fetchtimes.json"
+    RLSLOCAL=$(date -d "$(stat -c %z $RLSPATH)" +"%e %b %Y, %T %Z")
+    RLSUTC=$(date -d "$(stat -c %z $RLSPATH)" -u +"%e %b %Y, %T %Z")
+    echo "Last repo sync: $RLSLOCAL / $RLSUTC"
+}
+
 function reposync() {
     case `uname -s` in
         Darwin)