aosp-merge.sh: update branch name to android-7.0-merge

Change-Id: I57aaca9edd63b240191f8eb85469a44012e4b49d
diff --git a/utils/aosp-merge.sh b/utils/aosp-merge.sh
index 63af702..1596dad 100755
--- a/utils/aosp-merge.sh
+++ b/utils/aosp-merge.sh
@@ -35,11 +35,11 @@
 
     repo sync -d .
 
-    if git branch | grep "android-6.0-merge" > /dev/null; then
-        git branch -D android-6.0-merge > /dev/null
+    if git branch | grep "android-7.0-merge" > /dev/null; then
+        git branch -D android-7.0-merge > /dev/null
     fi
 
-    repo start android-6.0-merge .
+    repo start android-7.0-merge .
 
     if ! git remote | grep "aosp" > /dev/null; then
         git remote add aosp https://android.googlesource.com/platform/$path > /dev/null