Android: Upgrade AGP to 8.7.3 and bump minSdkVersion to 21

So that it builds with the latest Android Studio.

android/README.md

@@ -1,13 +1,12 @@
 # System3 for Android
 
+Minimum supported Android version: 5.0
+
 ## Download
 You can download prebuilt APKs
 [here](https://github.com/kichikuou/system3-sdl2/releases).
 
 ## Build
-Prerequisites:
-- Android SDK >=28
-- Android NDK >=r15c
 
 ### Using Android Studio
 Clone this repository along with its submodules:
@@ -28,8 +27,8 @@ sudo apt install git wget unzip default-jdk-headless ninja-build
 # Install Android SDK / NDK
 export ANDROID_SDK_ROOT=$HOME/android-sdk
 mkdir -p $ANDROID_SDK_ROOT/cmdline-tools
-wget https://dl.google.com/android/repository/commandlinetools-linux-10406996_latest.zip
-unzip commandlinetools-linux-10406996_latest.zip -d $ANDROID_SDK_ROOT/cmdline-tools
+wget https://dl.google.com/android/repository/commandlinetools-linux-11076708_latest.zip
+unzip commandlinetools-linux-11076708_latest.zip -d $ANDROID_SDK_ROOT/cmdline-tools
 mv $ANDROID_SDK_ROOT/cmdline-tools/cmdline-tools $ANDROID_SDK_ROOT/cmdline-tools/tools
 yes | $ANDROID_SDK_ROOT/cmdline-tools/tools/bin/sdkmanager --licenses
 $ANDROID_SDK_ROOT/cmdline-tools/tools/bin/sdkmanager ndk-bundle 'cmake;3.22.1'

android/app/build.gradle

@@ -14,7 +14,7 @@ android {
     }
     compileSdkVersion 34
     defaultConfig {
-        minSdkVersion 19
+        minSdkVersion 21
         targetSdkVersion 34
         versionCode 16
         versionName "1.5.0" + gitRevision()

android/build.gradle

@@ -7,7 +7,7 @@ buildscript {
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:8.1.1'
+        classpath 'com.android.tools.build:gradle:8.7.3'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong

android/gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 #Thu Nov 11 18:20:34 PST 2021
 distributionBase=GRADLE_USER_HOME
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.1.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.12-bin.zip
 distributionPath=wrapper/dists
 zipStorePath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME