Switch to Android 14 for physical device firebase tests (#47016)

Switch to the latest android version for tests.

Device is high capacity, and [currently in use in flutter/flutter](https://github.com/flutter/flutter/blob/dbb79e63ebdfdc0f11c9d1ab4125a80384a59d56/.ci.yaml#L451). See [here](https://firebase.google.com/docs/test-lab/android/available-testing-devices) to get the list of devices.

Related to https://github.com/flutter/flutter/pull/136736

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

ci/firebase_testlab.py

diff --git a/ci/firebase_testlab.py b/ci/firebase_testlab.py
index 72cc2c9..2709d14 100755
--- a/ci/firebase_testlab.py
+++ b/ci/firebase_testlab.py
@@ -54,7 +54,7 @@
           '--results-dir',
           results_dir,
           '--device',
-          'model=panther,version=33',
+          'model=shiba,version=34',
       ],
       stdout=subprocess.PIPE,
       stderr=subprocess.STDOUT,