update gradle and compose, make subtle changes to ui

app/build.gradle

@@ -1,54 +1,54 @@
 apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
-apply plugin: 'kotlin-android-extensions'
 
 android {
-  compileSdkVersion 29
+    compileSdkVersion 31
 
-  defaultConfig {
-    applicationId "com.snakydesign.jetpackcomposeparticles"
-    minSdkVersion 21
-    targetSdkVersion 29
-    versionCode 1
-    versionName "1.0"
+    defaultConfig {
+        applicationId "com.snakydesign.jetpackcomposeparticles"
+        minSdkVersion 21
+        targetSdkVersion 31
+        versionCode 1
+        versionName "1.0"
 
-    testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
-  }
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
 
 
-  kotlinOptions {
-    jvmTarget = "1.8"
-  }
-  buildFeatures {
-    compose true
-  }
-  buildTypes {
-    release {
-      minifyEnabled false
-      proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+    buildFeatures {
+        compose true
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+    composeOptions {
+        kotlinCompilerExtensionVersion compose_version
+    }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
     }
-  }
-  compileOptions {
-    sourceCompatibility JavaVersion.VERSION_1_8
-    targetCompatibility JavaVersion.VERSION_1_8
-  }
 }
 
 dependencies {
-  implementation fileTree(dir: "libs", include: ["*.jar"])
-  implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
-  implementation 'androidx.core:core-ktx:1.1.0'
-  implementation 'androidx.appcompat:appcompat:1.1.0'
-  implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
-  testImplementation 'junit:junit:4.12'
-  androidTestImplementation 'androidx.test.ext:junit:1.1.1'
-  androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+    implementation fileTree(dir: "libs", include: ["*.jar"])
+    implementation 'androidx.core:core-ktx:1.7.0'
+    implementation 'androidx.appcompat:appcompat:1.3.1'
+    implementation 'com.google.android.material:material:1.4.0'
+    implementation "androidx.compose.ui:ui:$compose_version"
+    implementation "androidx.compose.material:material:$compose_version"
+    implementation "androidx.compose.ui:ui-tooling-preview:$compose_version"
+    implementation 'androidx.activity:activity-compose:1.4.0'
 
-  implementation("androidx.compose:compose-runtime:$compose_version")
-  implementation("androidx.ui:ui-framework:$compose_version")
-  implementation("androidx.ui:ui-layout:$compose_version")
-  implementation("androidx.ui:ui-material:$compose_version")
-  implementation("androidx.ui:ui-foundation:$compose_version")
-  implementation("androidx.ui:ui-animation:$compose_version")
-  implementation "androidx.ui:ui-tooling:$compose_version"
+    testImplementation 'junit:junit:4.13.2'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
+    androidTestImplementation "androidx.compose.ui:ui-test-junit4:$compose_version"
+    debugImplementation "androidx.compose.ui:ui-tooling:$compose_version"
 }

app/src/main/AndroidManifest.xml

@@ -11,6 +11,7 @@
         android:theme="@style/AppTheme">
         <activity
             android:name=".ClockActivity"
+            android:exported="true"
             android:label="@string/title_activity_main2"
             android:theme="@style/AppTheme.NoActionBar">
             <intent-filter>