Add start/end padding to HistoryItem header.

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:fontFamily="sans-serif-medium"

        android:paddingStart="@dimen/history_item_text_padding_start"

        android:paddingEnd="@dimen/history_item_text_padding_end"

        android:text="@string/title_current_expression"

        android:textColor="?android:attr/colorAccent"

        android:textSize="14dp" />