Improve Cuttlefish boot reliability with stable build fallback (#4714)

This commit modifies the `flash_to_latest_build_if_needed` function to
include a fallback mechanism for booting Cuttlefish. If the device fails
to boot using the tip-of-the-tree build, the system will now attempt to
boot using a stable build retrieved from GCS.

#3950

Author: aditya-wazir

src/clusterfuzz/_internal/platforms/android/fetch_artifact.py

@@ -201,15 +201,15 @@ def get_stable_build_info():
   return stable_build_info
 
 
-def get_latest_artifact_info(branch, target, signed=False):
+def get_latest_artifact_info(branch, target, signed=False, stable_build=False):
   """Return latest artifact for a branch and target."""
   client = get_client()
   if not client:
     return None
 
   # TODO(https://github.com/google/clusterfuzz/issues/3950)
   # After stabilizing the Cuttlefish image, revert this
-  if environment.is_android_cuttlefish():
+  if environment.is_android_cuttlefish() and stable_build:
     build_info = get_stable_build_info()
     # Use tip-of-tree build if 'bid' is missing or 0.
     # Setting 'bid' to 0 in stable_build_info.json

src/clusterfuzz/_internal/platforms/android/flash.py

@@ -91,6 +91,15 @@ def download_latest_build(build_info, image_regexes, image_directory):
           reader.extract_all(image_directory)
 
 
+def boot_stable_build_cuttlefish(branch, target, image_directory):
+  """Boot cuttlefish instance using stable build id fetched from gcs."""
+  build_info = fetch_artifact.get_latest_artifact_info(
+      branch, target, stable_build=True)
+  download_latest_build(build_info, FLASH_CUTTLEFISH_REGEXES, image_directory)
+  adb.recreate_cuttlefish_device()
+  adb.connect_to_cuttlefish_device()
+
+
 def flash_to_latest_build_if_needed():
   """Wipes user data, resetting the device to original factory state."""
   if environment.get_value('LOCAL_DEVELOPMENT'):
@@ -207,12 +216,19 @@ def flash_to_latest_build_if_needed():
     locks.release_lock(flash_lock_key_name, by_zone=True)
 
   if adb.get_device_state() != 'device':
-    monitoring_metrics.CF_TIP_BOOT_FAILED_COUNT.increment({
-        'build_id': build_info['bid'],
-        'is_succeeded': False
-    })
-    logs.error('Unable to find device. Reimaging failed.')
-    adb.bad_state_reached()
+    if environment.is_android_cuttlefish():
+      logs.info('Trying to boot cuttlefish instance using stable build.')
+      monitoring_metrics.CF_TIP_BOOT_FAILED_COUNT.increment({
+          'build_id': build_info['bid'],
+          'is_succeeded': False
+      })
+      boot_stable_build_cuttlefish(branch, target, image_directory)
+      if adb.get_device_state() != 'device':
+        logs.error('Unable to find device. Reimaging failed.')
+        adb.bad_state_reached()
+    else:
+      logs.error('Unable to find device. Reimaging failed.')
+      adb.bad_state_reached()
 
   monitoring_metrics.CF_TIP_BOOT_FAILED_COUNT.increment({
       'build_id': build_info['bid'],