Reverts "Bump to Android API 34" (#791)

Reverts #790
Initiated by: gmackall
This change reverts the following previous change:
Original Description:
See the last time this was done #601. 

Needed to bump the engine to use Android 14.

New version was just uploaded https://chrome-infra-packages.appspot.com/p/flutter/android/sdk/all

build/config/android/config.gni

@@ -16,8 +16,8 @@ if (is_android) {
 
   if (!defined(default_android_sdk_root)) {
     default_android_sdk_root = "//third_party/android_tools/sdk"
-    default_android_sdk_version = "34"
-    default_android_sdk_build_tools_version = "34.0.0"
+    default_android_sdk_version = "33"
+    default_android_sdk_build_tools_version = "33.0.0"
   }
 
   declare_args() {