add disabled state (#1941)

Co-authored-by: AlexanderAlferov <64849422+AlexanderAlferov@users.noreply.github.com>
Co-authored-by: Ralf Gehrer <ralfgehrer@users.noreply.github.com>

Corona-Warn-App/src/main/res/color/button_red.xml

 <?xml version="1.0" encoding="utf-8"?>
 <selector xmlns:android="http://schemas.android.com/apk/res/android">
     <item android:color="@color/colorSemanticHighRiskPressed" android:state_pressed="true" /> <!-- pressed -->
+    <item android:color="@color/colorSurface2" android:state_enabled="false" /> <!-- disabled -->
     <item android:color="@color/colorSemanticHighRisk" /> <!-- default -->
-</selector>
\ No newline at end of file
+</selector>

Corona-Warn-App/src/main/res/layout/contact_diary_edit_locations_fragment.xml

@@ -75,7 +75,7 @@
             app:layout_constraintTop_toBottomOf="@id/toolbar"
             app:layout_constraintBottom_toTopOf="@id/delete_button"/>
 
-        <Button
+        <android.widget.Button
             android:id="@+id/delete_button"
             style="@style/buttonReset"
             android:layout_width="@dimen/match_constraint"

Corona-Warn-App/src/main/res/layout/contact_diary_edit_persons_fragment.xml

@@ -75,7 +75,7 @@
             app:layout_constraintTop_toBottomOf="@id/toolbar"
             app:layout_constraintBottom_toTopOf="@id/delete_button"/>
 
-        <Button
+        <android.widget.Button
             android:id="@+id/delete_button"
             style="@style/buttonReset"
             android:layout_width="@dimen/match_constraint"