title: After upgrading from Android gradle plugin version 3.6.4 to 4.2.1 i got attrs.xml:11:4: Invalid value 'null' for <enum>
body: <p>I tried to upgrade my Android projects targetSdkVersion from 30 to 31
  Therefore i upgraded Android gradle plugin 'com.android.tools.build:gradle:3.6.4' to
  'com.android.tools.build:gradle:4.2.1'</p>
  <p>gradle version is 6.7.1</p>
  <p>i got<br />
  .../app/src/main/res/values/attrs.xml:11:4: Invalid value 'null' for . Must be an integer. (--scan option)</p>
  <p>error message start <code>Exception is: org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:mergeDemoDebugResources'.</code></p>
  <p>here is my attrs.xml file</p>
  <pre><code>&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
  &lt;resources&gt;
      &lt;declare-styleable name=&quot;GlobalStyleable&quot;&gt;
          &lt;attr name=&quot;title&quot; format=&quot;string&quot; /&gt;
          &lt;attr name=&quot;text&quot; format=&quot;string&quot; /&gt;
          &lt;attr name=&quot;description&quot; format=&quot;string&quot; /&gt;
          &lt;attr name=&quot;enabled&quot; format=&quot;boolean&quot; /&gt;
          &lt;attr name=&quot;actionText&quot; format=&quot;string&quot; /&gt;
          &lt;attr name=&quot;endIcon&quot; format=&quot;reference&quot; /&gt;
      &lt;/declare-styleable&gt;
   
      &lt;declare-styleable name=&quot;SimpleEditText&quot;&gt;
          &lt;attr name=&quot;android:enabled&quot; /&gt;
          &lt;attr name=&quot;title&quot; /&gt;
          &lt;attr name=&quot;text&quot; /&gt;
          &lt;attr name=&quot;description&quot; /&gt;
          &lt;attr name=&quot;error&quot; format=&quot;string&quot; /&gt;
          &lt;attr name=&quot;endIconMode&quot; /&gt;
          &lt;attr name=&quot;endIconDrawable&quot; /&gt;
          &lt;attr name=&quot;inputType&quot; format=&quot;enum&quot;&gt;
              &lt;enum name=&quot;text&quot; value=&quot;0x00000001&quot; /&gt;
              &lt;enum name=&quot;password&quot; value=&quot;0x00000081&quot; /&gt;
              &lt;enum name=&quot;passwordWithoutKeyboard&quot; value=&quot;0x00000081&quot; /&gt;
              &lt;enum name=&quot;number&quot; value=&quot;0x00000002&quot; /&gt;
          &lt;/attr&gt;
          &lt;attr name=&quot;contextMenu&quot; format=&quot;enum&quot;&gt;
              &lt;enum name=&quot;full&quot; value=&quot;0&quot; /&gt;
              &lt;enum name=&quot;onlyCopy&quot; value=&quot;1&quot; /&gt;
              &lt;enum name=&quot;onlyPaste&quot; value=&quot;2&quot; /&gt;
              &lt;enum name=&quot;none&quot; value=&quot;3&quot; /&gt;
          &lt;/attr&gt;
          &lt;attr name=&quot;mask&quot; format=&quot;enum&quot;&gt;
              &lt;enum name=&quot;phone&quot; value=&quot;0&quot; /&gt;
              &lt;enum name=&quot;card&quot; value=&quot;1&quot; /&gt;
              &lt;enum name=&quot;bin&quot; value=&quot;2&quot; /&gt;
              &lt;enum name=&quot;account&quot; value=&quot;3&quot; /&gt;
              &lt;enum name=&quot;symbol2&quot; value=&quot;4&quot; /&gt;
              &lt;enum name=&quot;symbol3&quot; value=&quot;5 &quot; /&gt;
              &lt;enum name=&quot;smsCode&quot; value=&quot;6&quot; /&gt;
              &lt;enum name=&quot;password&quot; value=&quot;7&quot; /&gt;
          &lt;/attr&gt;
      &lt;/declare-styleable&gt;
   
      &lt;declare-styleable name=&quot;SimpleEditTextWithStartDrawable&quot;&gt;
          &lt;attr name=&quot;android:enabled&quot; /&gt;
          &lt;attr name=&quot;title&quot; /&gt;
          &lt;attr name=&quot;text&quot; /&gt;
          &lt;attr name=&quot;description&quot; /&gt;
          &lt;attr name=&quot;error&quot; /&gt;
          &lt;attr name=&quot;endIconMode&quot; /&gt;
          &lt;attr name=&quot;endIconDrawable&quot; /&gt;
          &lt;attr name=&quot;inputType&quot; /&gt;
          &lt;attr name=&quot;contextMenu&quot; /&gt;
          &lt;attr name=&quot;mask&quot; /&gt;
      &lt;/declare-styleable&gt;
   
      &lt;declare-styleable name=&quot;ProgressButton&quot;&gt;
          &lt;attr name=&quot;android:text&quot; /&gt;
          &lt;attr name=&quot;loading&quot; format=&quot;boolean&quot; /&gt;
      &lt;/declare-styleable&gt;
  &lt;/resources&gt;
  </code></pre>
  <p>please help</p>