Load Android Gradle Plugin conditionally

Author: SaeedZhiany

android/build.gradle

@@ -5,7 +5,7 @@ def getPackageVersion() {
 }
 
 def safeExtGet(prop, fallback) {
-    return rootProject.ext.hasProperty(prop) ? rootProject.ext.get(prop) : fallback
+    return rootProject.ext.has(prop) ? rootProject.ext.get(prop) : fallback
 }
 
 def _buildToolsVersion  = safeExtGet('buildToolsVersion', '28.0.3')
@@ -14,12 +14,18 @@ def _targetSdkVersion   = safeExtGet('targetSdkVersion', 28)
 def _minSdkVersion      = safeExtGet('minSdkVersion', 16)
 
 buildscript {
-    repositories {
-        google()
-        jcenter()
-    }
-    dependencies {
-        classpath 'com.android.tools.build:gradle:3.4.1'
+    // The Android Gradle plugin is only required when opening the android folder stand-alone.
+    // This avoids unnecessary downloads and potential conflicts when the library is included as a
+    // module dependency in an application project.
+    if (project == rootProject) {
+        repositories {
+            google()
+            jcenter()
+        }
+
+        dependencies {
+            classpath("com.android.tools.build:gradle:3.5.3")
+        }
     }
 }