[Android] Refactor the buildbot scripts to prepare for downstream usage.

build/android/buildbot/bb_utils.py

Index: build/android/buildbot/bb_utils.py
diff --git a/build/android/buildbot/bb_utils.py b/build/android/buildbot/bb_utils.py
index 74b27923da8a7b910b62e246baaaa12449231bff..dccc63516f03d66d78feec34d9839a31964f9017 100644
--- a/build/android/buildbot/bb_utils.py
+++ b/build/android/buildbot/bb_utils.py
@@ -78,16 +78,17 @@ def EncodeProperties(options):
           '--build-properties=%s' % json.dumps(options.build_properties)]
 
 
-def RunSteps(all_steps, options):
-  if not options.steps:
-    return
-
-  steps = options.steps.split(',')
-  unknown_steps = set(steps) - set(step for step, _ in all_steps)
+def RunSteps(steps, step_cmds, options):
+  unknown_steps = set(steps) - set(step for step, _ in step_cmds)
   if unknown_steps:
     print >> sys.stderr, 'FATAL: Unknown steps %s' % list(unknown_steps)
     sys.exit(1)
 
-  for step, cmd in all_steps:
+  for step, cmd in step_cmds:
     if step in steps:
       cmd(options)
+
+
+def RunAllSteps(step_cmds, options):
+  for _, cmd in step_cmds:
+    cmd(options)