Smaller font size for reader page indicator (closes #6071)

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

@@ -22,7 +22,7 @@
             android:layout_height="wrap_content"
             android:layout_gravity="bottom|center_horizontal"
             android:padding="4dp"
-            android:textAppearance="?attr/textAppearanceSubtitle2"
+            android:textAppearance="?attr/textAppearanceCaption"
             android:textDirection="ltr"
             android:textStyle="bold" />