Android: Update and add missing gradle files for jar folders

Update the build.gradle for main Qt jar code, and add same files for
network and network information backend, so the code can be managed
from Android Studio.

This also adds .gitignore to ignore Android Studio build artefacts.

Pick-to: 6.2
Change-Id: Ic06e9d12708070fad112f17e58b8754608d184f3
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

src/android/jar/build.gradle

@@ -3,11 +3,11 @@
 buildscript {
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.0.2'
+        classpath 'com.android.tools.build:gradle:7.0.2'
     }
 }
 
@@ -15,21 +15,20 @@ apply plugin: 'com.android.library'
 
 dependencies {
     implementation fileTree(dir: "libs", include: ["*.jar"])
-//     implementation 'androidx.appcompat:appcompat:1.2.0' // for androidx
 }
 
 repositories {
     google()
-    jcenter()
+    mavenCentral()
 }
 
 android {
-    compileSdkVersion 30
-    buildToolsVersion "30.0.3"
+    compileSdkVersion 31
+    buildToolsVersion "31.0.3"
 
     defaultConfig {
         minSdkVersion 23
-        targetSdkVersion 30
+        targetSdkVersion 31
     }
 
     sourceSets {

src/network/android/jar/.gitignore

@@ -0,0 +1,6 @@
+.gradle/
+build/
+gradle/
+gradlew
+gradlew.bat
+local.properties

src/network/android/jar/build.gradle

@@ -0,0 +1,53 @@
+// This is mainly used to allow Android Studio to easily read this folder as an android project.
+
+buildscript {
+    repositories {
+        google()
+        mavenCentral()
+    }
+
+    dependencies {
+        classpath 'com.android.tools.build:gradle:7.0.2'
+    }
+}
+
+apply plugin: 'com.android.library'
+
+dependencies {
+    implementation fileTree(dir: "libs", include: ["*.jar"])
+}
+
+repositories {
+    google()
+    mavenCentral()
+}
+
+android {
+    compileSdkVersion 31
+    buildToolsVersion "31.0.3"
+
+    defaultConfig {
+        minSdkVersion 23
+        targetSdkVersion 31
+    }
+
+    sourceSets {
+        main {
+            java.srcDir 'src/'
+            resources.srcDir 'libs/'
+            manifest.srcFile 'AndroidManifest.xml'
+            res.srcDirs = ['res/']
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    android {
+        lintOptions {
+            abortOnError true
+        }
+    }
+}

src/network/android/jar/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = "QtAndroidNetwork"

src/plugins/networkinformation/android/jar/.gitignore

@@ -0,0 +1,6 @@
+.gradle/
+build/
+gradle/
+gradlew
+gradlew.bat
+local.properties

src/plugins/networkinformation/android/jar/build.gradle

@@ -0,0 +1,53 @@
+// This is mainly used to allow Android Studio to easily read this folder as an android project.
+
+buildscript {
+    repositories {
+        google()
+        mavenCentral()
+    }
+
+    dependencies {
+        classpath 'com.android.tools.build:gradle:7.0.2'
+    }
+}
+
+apply plugin: 'com.android.library'
+
+dependencies {
+    implementation fileTree(dir: "libs", include: ["*.jar"])
+}
+
+repositories {
+    google()
+    mavenCentral()
+}
+
+android {
+    compileSdkVersion 31
+    buildToolsVersion "31.0.3"
+
+    defaultConfig {
+        minSdkVersion 23
+        targetSdkVersion 31
+    }
+
+    sourceSets {
+        main {
+            java.srcDir 'src/'
+            resources.srcDir 'libs/'
+            manifest.srcFile 'AndroidManifest.xml'
+            res.srcDirs = ['res/']
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    android {
+        lintOptions {
+            abortOnError true
+        }
+    }
+}

src/plugins/networkinformation/android/jar/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = "QtAndroidNetworkInformationBackend"