ci(ftl): use Pixel 7 codename 'panther' (Pixel7 friendly name deprecated)

FTL catalog renamed friendly names to device codenames. Pixel 7 is now
'panther', Galaxy S22 stays 'b0q'. Confirmed by the previous run's error:
"'Pixel7' is not a valid model".

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ithiria894

.github/workflows/firebase-test-lab.yml

@@ -126,7 +126,7 @@ jobs:
           gcloud firebase test android run \
             --type robo \
             --app "$APK" \
-            --device model=Pixel7,version=33,locale=en,orientation=portrait \
+            --device model=panther,version=33,locale=en,orientation=portrait \
             --device model=b0q,version=33,locale=en,orientation=portrait \
             --timeout 5m \
             --num-flaky-test-attempts=0 \