Add a renderer key to lottie gold digests

This will help us distinguish between "rendered by skottie",
"rendered by lottie-web", etc.

Bug: skia:8108
Change-Id: I48b489adf8f8b7f950df397e5e94c1103dc4d306
Reviewed-on: https://skia-review.googlesource.com/149237
Reviewed-by: Stephan Altmueller <stephana@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>

infra/bots/recipes/test.expected/Test-Debian9-Clang-GCE-CPU-AVX2-x86_64-Release-All-Lottie.json

@@ -195,6 +195,8 @@
       "GCE",
       "os",
       "Debian9",
+      "renderer",
+      "skottie",
       "--uninterestingHashesFile",
       "[START_DIR]/tmp/uninteresting_hashes.txt",
       "--writePath",

infra/bots/recipes/test.expected/Test-Ubuntu17-Clang-Golo-GPU-QuadroP400-x86_64-Debug-All-Lottie.json

@@ -195,6 +195,8 @@
       "Golo",
       "os",
       "Ubuntu17",
+      "renderer",
+      "skottie",
       "--uninterestingHashesFile",
       "[START_DIR]/tmp/uninteresting_hashes.txt",
       "--writePath",

infra/bots/recipes/test.py

@@ -821,6 +821,7 @@ def key_params(api):
     if k not in blacklist:
       flat.append(k)
       flat.append(api.vars.builder_cfg[k])
+
   return flat
 
 
@@ -928,7 +929,12 @@ def test_steps(api):
       args.extend(['--lotties', api.flavor.device_dirs.lotties_dir])
 
   args.append('--key')
-  args.extend(key_params(api))
+  keys = key_params(api)
+
+  if 'Lottie' in api.vars.builder_cfg.get('extra_config', ''):
+    keys.extend(['renderer', 'skottie'])
+
+  args.extend(keys)
 
   if use_hash_file:
     args.extend(['--uninterestingHashesFile', hashes_file])