[3.14] gh-142387: Reduce Android testbed API level to 33 (GH-144315) (#144317)

The emulator images for API level 34 and 35 have significant issues with image size and
internet connectivity. Reverts the default API level used for testbed testing to 33.
(cherry picked from commit 6543720)

Co-authored-by: Malcolm Smith <smith@chaquo.com>

Author: miss-islington

Android/testbed/app/build.gradle.kts

@@ -92,7 +92,12 @@ android {
             }
             throw GradleException("Failed to find API level in $androidEnvFile")
         }
-        targetSdk = 35
+
+        // This controls the API level of the maxVersion managed emulator, which is used
+        // by CI and cibuildwheel. 34 takes up too much disk space (#142289), 35 has
+        // issues connecting to the internet (#142387), and 36 and later are not
+        // available as aosp_atd images yet.
+        targetSdk = 33
 
         versionCode = 1
         versionName = "1.0"