Small font changes to the test result cards on homescreen (#384)

Co-authored-by: Hee Tatt Ooi <hee.tatt.ooi@sap.com>
Co-authored-by: Jakob Möller <jakob.moeller@sap.com>
Co-authored-by: harambasicluka <64483219+harambasicluka@users.noreply.github.com>

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

@@ -36,7 +36,7 @@
 
         <TextView
             android:id="@+id/submission_status_card_content_subtitle"
-            style="@style/subtitleMedium"
+            style="@style/headline6"
             android:layout_width="@dimen/match_constraint"
             android:layout_height="wrap_content"
             android:layout_marginStart="@dimen/card_padding"
@@ -53,7 +53,7 @@
 
         <TextView
             android:id="@+id/submission_status_card_content_body"
-            style="@style/subtitle"
+            style="@style/subtitleMedium"
             android:layout_width="@dimen/match_constraint"
             android:layout_height="wrap_content"
             android:layout_marginStart="@dimen/card_padding"