admob compile error

Compiling code.                         0.02
Compiling layouts code.                 0.00
Generating R file.                      0.00
Compiling generated Java code.          0.77
Convert byte code - optimized dex.      0.66
Packaging files.                        Error
AndroidManifest.xml:20: error: Error: String types not allowed (at 'configChanges' with value 'keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize').

'AdMob
AddApplicationText(
 <activity android:name="com.google.ads.AdActivity"
  android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"/>
)
'End of AdMob