[Android] Improve building. (software-mansion#900)

WHY:
To speed up building.

HOW:
1 Added necessary tasks to Android/build.gradle similar to tasks from react-native/ReactAndroid/build.gradle.
2 Created Application.mk
3 Created Android.mk
4 Add important lines from ReactAndroid/src/main/jni/react/jni/Android.mk (I've tried to import/include this module but it didn't work)
5 update createNPMPackage.sh

.gitignore

@@ -28,6 +28,7 @@ project.xcworkspace
 .idea
 .gradle
 local.properties
+android/src/main/JNILibs/
 
 # node.js
 #

Example/android/app/build.gradle

@@ -160,7 +160,7 @@ dependencies {
     implementation project(':react-native-gesture-handler')
 
     implementation fileTree(dir: "libs", include: ["*.jar"])
-    implementation project(':react-native')// From node_modules
+    implementation "com.facebook.react:react-native:+"  // From node_modules
     //implementation 'org.webkit:android-jsc:+'
 
     implementation "androidx.swiperefreshlayout:swiperefreshlayout:1.0.0"

Example/android/build.gradle

@@ -19,14 +19,6 @@ buildscript {
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }
-
-    configurations.all {
-        resolutionStrategy {
-            dependencySubstitution {
-                substitute module("com.facebook.react:react-native:+") with project(":react-native")
-            }
-        }
-    }
 }
 
 allprojects {

Example/android/settings.gradle

@@ -7,6 +7,4 @@ include ':react-native-reanimated'
 project(':react-native-reanimated').projectDir = new File(rootProject.projectDir, '../../android')
 include ':react-native-gesture-handler'
 project(':react-native-gesture-handler').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-gesture-handler/android')
-include ':react-native'
-project(':react-native').projectDir = new File(rootProject.projectDir, '../node_modules/react-native/ReactAndroid')
 include ':app'