StateListAnimator is overwriting the Drawable on "background"?

I am trying to add a fade-in and fade-out effect on a LinearLayout backgroundColor property based on state_selected. For background I have set a drawable (in android:background) and for animation I have added animation (in android:stateListAnimator).

The animation is working fine when I select and unselect the View, but after adding this stateListAnimator, my background drawable is gone or maybe overwritten by animator.

Here is my code for the View:

    <LinearLayout
            android:id="@+id/long_term_plan"
            android:layout_width="157dp"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:padding="12dp"
            android:background="@drawable/premium_page_plan_button_background"
            android:stateListAnimator="@animator/premium_button_animation" >

            <TextView
                android:id="@+id/long_term_title"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textColor="@color/black"
                android:textSize="14sp"
                android:fontFamily="@font/work_sans_bold"
                android:text="@string/long_term_title" />

            <TextView
                android:id="@+id/long_term_discount_text"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textColor="@color/premium_savings_text"
                android:textSize="12sp"
                android:textStyle="bold"
                android:paddingTop="6dp"
                android:fontFamily="@font/work_sans_light"
                android:text="@string/long_term_discount_text"/>

            <TextView
                android:id="@+id/long_term_original_price"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_marginTop="12dp"
                android:fontFamily="@font/work_sans_bold"
                android:text="@string/long_term_original_price"
                android:textColor="@color/original_price_color"
                android:textSize="20sp"
                android:textStyle="bold"/>

        </LinearLayout>

@drawable/premium_page_plan_button_background.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true">
        <shape android:shape="rectangle">
            <solid android:color="@color/light_gray"/>
            <corners android:radius="8dp"/>
            <stroke android:width="1dp"
                android:color="@color/gray_border"/>
        </shape>
    </item>
    <item android:state_selected="false">
        <shape android:shape="rectangle">
            <solid android:color="@color/light_black"/>
            <corners android:radius="8dp"/>
            <stroke android:width="1dp"
                android:color="@color/gray_border"/>
        </shape>
    </item>
</selector>

@animator/premium_button_animation.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true">
        <set>
            <objectAnimator android:propertyName="backgroundColor"
                android:valueFrom="@color/light_black"
                android:valueTo="@color/light_gray"
                android:duration="200" />
        </set>

    </item>
    <item android:state_selected="false">
        <set>
            <objectAnimator android:propertyName="backgroundColor"
                android:valueFrom="@color/light_gray"
                android:valueTo="@color/light_black"
                android:duration="200" />
        </set>
    </item>
</selector>

My drawable effect before adding animator: before animator

My drawable effect after adding animator: after animator

How can I achieve use both drawable and animator together, or am I doing something wrong here??

Any help would be appreciated!!

PS: I am handling all this animation in xml itself. For triggering the state_selected, I am using the onCLickListener in java activity.