android build: factor out package name ("org.electrum.electrum")

to make it easier to change, to make it easy to have a co-existing mainnet and testnet install
(or two mainnet installs, etc)

electrum/logging.py

@@ -310,17 +310,15 @@ class Logger:
 
 
 def configure_logging(config: 'SimpleConfig', *, log_to_file: Optional[bool] = None) -> None:
+    from .util import is_android_debug_apk
+
     verbosity = config.get('verbosity')
     verbosity_shortcuts = config.get('verbosity_shortcuts')
     _configure_stderr_logging(verbosity=verbosity, verbosity_shortcuts=verbosity_shortcuts)
 
     if log_to_file is None:
         log_to_file = config.get('log_to_file', False)
-        is_android = 'ANDROID_DATA' in os.environ
-        if is_android:
-            from jnius import autoclass
-            build_config = autoclass("org.electrum.electrum.BuildConfig")
-            log_to_file |= bool(build_config.DEBUG)
+        log_to_file |= is_android_debug_apk()
     if log_to_file:
         log_directory = pathlib.Path(config.path) / "logs"
         _configure_file_logging(log_directory)

electrum/util.py

@@ -444,7 +444,8 @@ def android_ext_dir():
     return primary_external_storage_path()
 
 def android_backup_dir():
-    d = os.path.join(android_ext_dir(), 'org.electrum.electrum')
+    pkgname = get_android_package_name()
+    d = os.path.join(android_ext_dir(), pkgname)
     if not os.path.exists(d):
         os.mkdir(d)
     return d
@@ -511,6 +512,26 @@ def get_new_wallet_name(wallet_folder: str) -> str:
     return filename
 
 
+def is_android_debug_apk() -> bool:
+    is_android = 'ANDROID_DATA' in os.environ
+    if not is_android:
+        return False
+    from jnius import autoclass
+    pkgname = get_android_package_name()
+    build_config = autoclass(f"{pkgname}.BuildConfig")
+    return bool(build_config.DEBUG)
+
+
+def get_android_package_name() -> str:
+    is_android = 'ANDROID_DATA' in os.environ
+    assert is_android
+    from jnius import autoclass
+    from android.config import ACTIVITY_CLASS_NAME
+    activity = autoclass(ACTIVITY_CLASS_NAME).mActivity
+    pkgname = str(activity.getPackageName())
+    return pkgname
+
+
 def assert_bytes(*args):
     """
     porting helper, assert args type