android 6.1 for sqlcipher_flutter_libs

[Ali1Ammar]

i see there is error with dynamic link in old phone and some 6.1 device
there is applyWorkaroundToOpenSqlite3OnOldAndroidVersions for sqlite3_flutter_libs but not for sqlcipher_flutter_libs
also when we override like this as describe in moor docs will break old device because we need to use full path with id on old device

  open.overrideFor(
      OperatingSystem.android, () => DynamicLibrary.open('libsqlcipher.so'));

i suggest to add this to sqlcipher_flutter_libs :

1- applyWorkaroundToOpenSqlite3OnOldAndroidVersions

2- provide openCipherOnAndroid function that do this

DynamicLibrary openCipherOnAndroid() {
  try {
    return DynamicLibrary.open('libsqlcipher.so');
  } catch (_) {
    // On some (especially old) Android devices, we somehow can't dlopen
    // libraries shipped with the apk. We need to find the full path of the
    // library (/data/data/<id>/lib/libsqlcipher.so) and open that one.
    // For details, see https://github.com/simolus3/moor/issues/420
    final appIdAsBytes = File('/proc/self/cmdline').readAsBytesSync();

    // app id ends with the first \0 character in here.
    final endOfAppId = max(appIdAsBytes.indexOf(0), 0);
    final appId = String.fromCharCodes(appIdAsBytes.sublist(0, endOfAppId));

    return DynamicLibrary.open('/data/data/$appId/lib/libsqlcipher.so');
  }
}

then programmer could do

  open.overrideFor(
      OperatingSystem.android, openCipherOnAndroid);

i am happy to make pull request if this way ok .

[simolus3]

A pull request would be great, thanks 👍