🔧 (build.gradle): add namespace configuration for Android project

Introduce the `namespace` configuration under the `android` block to
specify the package name for the Android project. This change is
necessary to ensure that the project is correctly identified and
organized within the Android ecosystem, particularly when integrating
with libraries like CodePush. It helps in maintaining a clear
structure and avoiding potential conflicts with other packages.

Author: chlee1001

android/build.gradle

@@ -14,6 +14,9 @@ buildscript {
 }
 
 allprojects {
+    android {
+        namespace "com.microsoft.codepush.react"
+    }
     repositories {
         mavenLocal()
         mavenCentral()