Use xml parameter android:firstDayOfWeek with value from Calendar. 2 - is Monday.
<CalendarView
android:id="@+id/calendarView1"
android:firstDayOfWeek="2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="157dp" />
Or you can specify it from code
CalendarView calendarView = findViewById(R.id.calendarView1);
calendarView.setFirstDayOfWeek(Calendar.MONDAY);