Use fitCenter instead of centerCrop where sensible (commons-app#2149)

Author: domdomegg

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

@@ -26,7 +26,7 @@
                 android:id="@+id/backgroundImage"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
-                app:actualImageScaleType="centerCrop" />
+                app:actualImageScaleType="fitCenter" />
 
             <FrameLayout
                 android:id="@+id/single_upload_fragment_container"

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

@@ -23,7 +23,7 @@
             android:layout_height="match_parent"
             android:layout_below="@id/toolbar"
             android:background="@color/commons_app_blue_dark"
-            app:actualImageScaleType="centerCrop" />
+            app:actualImageScaleType="fitCenter" />
 
         <android.support.constraint.ConstraintLayout
             android:id="@+id/activity_upload_cards"

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

@@ -13,13 +13,13 @@
             android:layout_width="160dp"
             android:layout_height="240dp"
             android:layout_margin="3dp"
-            app:actualImageScaleType="centerCrop" />
+            app:actualImageScaleType="fitCenter" />
         <com.facebook.drawee.view.SimpleDraweeView
             android:id="@+id/possibleImage"
             android:layout_width="160dp"
             android:layout_height="240dp"
             android:layout_margin="3dp"
-            app:actualImageScaleType="centerCrop" />
+            app:actualImageScaleType="fitCenter" />
     </LinearLayout>
     <TextView
         android:layout_width="match_parent"

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

@@ -22,7 +22,7 @@
         android:id="@+id/contributionImage"
         android:layout_width="match_parent"
         android:layout_height="240dp"
-        app:actualImageScaleType="centerCrop"
+        app:actualImageScaleType="fitCenter"
         />
 
     <LinearLayout