new logo added, primary screen design update

- logo of app and notification updated to
  new orange design
- primary screen has prettier colors now
  and larger text for sender information

app/src/main/res/layout/fragment_first.xml

@@ -12,6 +12,7 @@
         android:layout_height="wrap_content"
         android:text="@string/current_sender"
         android:layout_marginTop="40dp"
+        android:textSize="20sp"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent" />
@@ -25,6 +26,7 @@
         android:breakStrategy="balanced"
         android:maxEms="16"
         android:visibility="gone"
+        android:textSize="18sp"
 
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
@@ -56,12 +58,14 @@
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_marginEnd="20dp"
+            android:textColor="@color/white"
             android:text="@string/scan_sender" />
 
         <Button
             android:id="@+id/button_view"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
+            android:textColor="@color/white"
             android:text="@string/view_sender" />
     </LinearLayout>
 </androidx.constraintlayout.widget.ConstraintLayout>