Add keystore and build on sign on release

.gitignore

@@ -13,3 +13,4 @@
 .externalNativeBuild
 .cxx
 .idea
+keystore.properties

app/build.gradle

@@ -1,6 +1,16 @@
 apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
 
+// Create a variable called keystorePropertiesFile, and initialize it to your
+// keystore.properties file, in the rootProject folder.
+def keystorePropertiesFile = rootProject.file("keystore.properties")
+
+// Initialize a new Properties() object called keystoreProperties.
+def keystoreProperties = new Properties()
+
+// Load your keystore.properties file into the keystoreProperties object.
+keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
+
 android {
     compileSdkVersion 32
 
@@ -13,12 +23,20 @@ android {
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
-
+    signingConfigs {
+        create("release") {
+            keyAlias = keystoreProperties["keyAlias"]
+            keyPassword = keystoreProperties["keyPassword"]
+            storeFile = file(keystoreProperties["storeFile"])
+            storePassword = keystoreProperties["storePassword"]
+        }
+    }
     buildTypes {
         release {
             minifyEnabled true
             shrinkResources true
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+            signingConfig = signingConfigs.getByName("release")
         }
     }