Rollback SDK and add deprecation warning

app/build.gradle

@@ -3,14 +3,15 @@ plugins {
 }
 
 android {
-    compileSdkVersion 33
+    compileSdkVersion 32
     buildToolsVersion "30.0.3"
     namespace "net.crystalyx.setaswallpaper"
 
     defaultConfig {
         applicationId "net.crystalyx.setaswallpaper"
         minSdkVersion 5
-        targetSdkVersion 33
+        //noinspection OldTargetApi
+        targetSdkVersion 32
         versionCode 8
         versionName "3.1"
     }
@@ -30,9 +31,11 @@ android {
         release {
             minifyEnabled true
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+            if (System.env.STORE_FILE) {
                 signingConfig signingConfigs.release
             }
         }
+    }
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8

build.gradle

@@ -17,6 +17,10 @@ allprojects {
         google()
         mavenCentral()
     }
+
+    tasks.withType(JavaCompile) {
+        options.deprecation = true
+    }
 }
 
 task clean(type: Delete) {