Visual update: remove card elevation for homepage cards.

- Replace CardView with MaterialCardView
- Add strokeColor and strokeWidth to MaterialCardView
- Set cardElevation to 0dp.

And remove a few unused layout, clean up color lint whitelist.

Test: rebuild, visual
Change-Id: I34a4b9a985cb85c212e123b8af5353d8c548923a

res/layout/homepage_condition_full_tile.xml

@@ -15,7 +15,7 @@
      limitations under the License.
 -->
 
-<androidx.cardview.widget.CardView
+<com.google.android.material.card.MaterialCardView
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
@@ -71,4 +71,4 @@
 
     </LinearLayout>
 
-</androidx.cardview.widget.CardView>
+</com.google.android.material.card.MaterialCardView>

res/layout/homepage_condition_half_tile.xml

@@ -15,7 +15,7 @@
      limitations under the License.
 -->
 
-<androidx.cardview.widget.CardView
+<com.google.android.material.card.MaterialCardView
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="@dimen/homepage_condition_half_card_height"
@@ -65,4 +65,4 @@
 
     </LinearLayout>
 
-</androidx.cardview.widget.CardView>
+</com.google.android.material.card.MaterialCardView>

res/layout/homepage_condition_header.xml

@@ -15,7 +15,7 @@
   limitations under the License.
   -->
 
-<androidx.cardview.widget.CardView
+<com.google.android.material.card.MaterialCardView
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
@@ -49,4 +49,4 @@
 
     </LinearLayout>
 
-</androidx.cardview.widget.CardView>
+</com.google.android.material.card.MaterialCardView>

res/layout/homepage_slice_tile.xml

@@ -15,7 +15,7 @@
      limitations under the License.
 -->
 
-<androidx.cardview.widget.CardView
+<com.google.android.material.card.MaterialCardView
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
@@ -70,4 +70,4 @@
             </LinearLayout>
         </LinearLayout>
     </ViewFlipper>
-</androidx.cardview.widget.CardView>
+</com.google.android.material.card.MaterialCardView>

res/layout/homepage_suggestion_tile.xml

@@ -15,7 +15,7 @@
   limitations under the License.
   -->
 
-<androidx.cardview.widget.CardView
+<com.google.android.material.card.MaterialCardView
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/suggestion_card"
     android:layout_width="match_parent"
@@ -67,4 +67,4 @@
 
     </LinearLayout>
 
-</androidx.cardview.widget.CardView>
+</com.google.android.material.card.MaterialCardView>