android: update building documentation

docs/building.md

 
 1.  the [Android Studio](https://developer.android.com/studio/) with API 26 support;
 2.  the [Android NDK](http://developer.android.com/tools/sdk/ndk/index.html);
-3.  Gradle 5.6.4
+3.  Gradle 7.4+
+4.  JDK 11
 
 ### Building with Gradle
 
         $ export ANDROID_HOME=<path-to-the-android-sdk>
 (where `<path-to-the-android-sdk>` is your actual path of SDK folder e.g. `/home/user/Android/Sdk`)
 
-2.  Add location of NDK to the PATH variable:
-
-        $ export PATH=$PATH:<path-to-the-android-ndk>
-(where `<path-to-the-android-ndk>` is your actual path of NDK folder, e.g. `/home/user/Android/Ndk`)
-
-3. Configure the project:
+2. Configure the project:
 
         $ ./autogen.sh
         $ ./configure --with-gradle=<path-to-gradle>
 
         ...
         gradle (Android):              gradle
-        ndk-build (Android):           yes
         ...
 `<path-to-gradle>` may be just `gradle` if it is found in your path by simple name.
 
-4. Build the project:
+3. Build the project:
 
         $ make apk-release
 
 To enable eSpeak, you need to:
 
 1.  go into the Android `Text-to-Speech settings` UI;
-2.  enable `eSpeak TTS` in the `Engines` section;
-3.  select `eSpeak TTS` as the default engine;
-4.  use the `Listen to an example` option to check if everything is working.
+2.  select `eSpeak TTS` as the default engine;
+3.  use the `Listen to an example` option to check if everything is working.