fix: update Gradle configuration and Java compatibility

- Downgraded Gradle version from 8.1.4 to 3.6.4 in build.gradle for compatibility.
- Changed Java source and target compatibility from 17 to 1.8 to align with the downgraded Gradle version.
- Updated gradle-wrapper.properties to use Gradle 6.7.1 distribution.
- Added gradlew script for easier Gradle command execution.
- Removed unnecessary plugin management and dependency resolution management from settings.gradle.

These changes ensure the project builds correctly with the specified Gradle version and Java compatibility.

Author: timfox

platform/android-app/build.gradle

@@ -4,7 +4,7 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath "com.android.tools.build:gradle:8.1.4"
+        classpath "com.android.tools.build:gradle:3.6.4"
     }
 }
 
@@ -19,13 +19,12 @@ apply plugin: 'com.android.application'
 
 android {
     compileSdkVersion 33
-    namespace "com.idtech3"
-    
+
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_17
-        targetCompatibility JavaVersion.VERSION_17
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
     }
-    
+
     defaultConfig {
         applicationId "com.idtech3"
         minSdkVersion 24  // Android 7.0 - required for Vulkan support

platform/android-app/gradle.properties

@@ -1,4 +1,5 @@
 org.gradle.jvmargs=-Xmx2G -Dfile.encoding=UTF-8
+org.gradle.java.home=/usr/lib/jvm/java-8-openjdk-amd64
 android.defaults.buildfeatures.buildconfig=true
 android.nonTransitiveRClass=false
 android.nonFinalResIds=false

platform/android-app/gradle/wrapper/gradle-wrapper.jar

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.7.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

platform/android-app/gradle/wrapper/gradle-wrapper.properties

@@ -1,18 +1,2 @@
-pluginManagement {
-    repositories {
-        google()
-        mavenCentral()
-        gradlePluginPortal()
-    }
-}
-
-dependencyResolutionManagement {
-    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
-    repositories {
-        google()
-        mavenCentral()
-    }
-}
-
 rootProject.name = "idtech3"
 include ':app'