How to properly remove padding (or margin?) around buttons in Android?

Question

Currently, I have the following bottom log in button.

When button is not being pressed

When button is being pressed

The XML loo

Answer 1

After trying lots of solution, Finally I came to a conclusion that with tag alone we can't achieve this. to remove this unwanted space around button my solution is as below:

 <RelativeLayout
    android:id="@+id/myButtonUnderlay"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom"
    android:visibility="visible">
<Button
    android:id="@+id/save_button"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_marginTop="-5dp" 
    android:layout_marginBottom="-5dp"
    android:layout_above="@+id/content_scrollview"
    android:layout_gravity="bottom"
    android:background="@drawable/ripple_theme"
    android:enabled="true"
    android:text="SetUp Store"
    android:textColor="#fff"
    android:textSize="18sp"
    android:visibility="gone"
    tools:visibility="visible"
    style="@style/MediumFontTextView" />
</RelativeLayout>