Rename XmlManifest.GetGroupsStr() to XmlManifest.GetManifestGroupsStr()

This makes it more clear what kind of groups it refers to.

Change-Id: I47369050d1436efcc77f3a69d5b7c99a536b23bc
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/528462
Tested-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Reviewed-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Reviewed-by: Mike Frysinger <vapier@google.com>

command.py

@@ -399,7 +399,7 @@ class Command:
         result = []
 
         if not groups:
-            groups = manifest.GetGroupsStr()
+            groups = manifest.GetManifestGroupsStr()
         groups = [x for x in re.split(r"[,\s]+", groups) if x]
 
         if not args: