title: Error changing build sdk in adroid studio
body: <p>When I change both the targetsSdkVersion and the compileSdkVersion to 26, i get an error. I have tried chnaging it through the Project structure settings, and manually, but it keeps giving me the following error:</p>
  
  <blockquote>
    <p>AAPT: error: resource android:attr/dialogCornerRadius not found.
    <img src="https://i.stack.imgur.com/THn4s.png" alt="error dialogCirnerRadius not found"></p>
  </blockquote>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 26
      defaultConfig {
          applicationId "com.example.agriplanner3"
          minSdkVersion 14
          targetSdkVersion 26
          versionCode 1
          versionName "1.0"
          testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
          }
      }
  }
  repositories {
      google()
  }
  
  dependencies {
      implementation fileTree(dir: 'libs', include: ['*.jar'])
      implementation 'androidx.appcompat:appcompat:1.1.0'
      implementation 'com.android.support:appcompat-v7:26.0.0'
      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'
  }
  </code></pre>