[Mfill Android] Consistent accessory shadows

This CL changes the accessory bar's top shadow to a "Toolbar Shadow" as
appropriate for a fixed piece of Chromium UI.
This would have the weird side effect of putting the accessory sheet on
the same perceived Z-level as the website. To prevent this, the
scrolling shadow changes to a smaller shadow that resembles the planned
"Modal shadow" which leverages the sheet above the website.

Screenshots and visual aids for this problem:
http://slides/1uto1gWimPsaU_3JVbNZqi7bk1tnsfVFV5Pgkck9cefM#slide=id.g482fab1c8c_0_265

Change-Id: I81451ac0605e601a4bd8ad6a511a2c2a050dc91c
Reviewed-on: https://chromium-review.googlesource.com/c/1348062Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Friedrich Horschig [CET] <fhorschig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611124}

chrome/android/java/res/layout/keyboard_accessory.xml

@@ -22,7 +22,7 @@
      <ImageView
         android:id="@+id/accessory_shadow"
         android:layout_width="match_parent"
-        android:layout_height="@dimen/keyboard_accessory_shadow"
+        android:layout_height="@dimen/toolbar_shadow_height"
         android:src="@drawable/modern_toolbar_shadow"
         android:scaleType="fitXY"
         android:scaleY="-1"

chrome/android/java/res/layout/keyboard_accessory_modern.xml

@@ -22,7 +22,7 @@
     <ImageView
         android:id="@+id/accessory_shadow"
         android:layout_width="match_parent"
-        android:layout_height="@dimen/keyboard_accessory_shadow"
+        android:layout_height="@dimen/toolbar_shadow_height"
         android:src="@drawable/modern_toolbar_shadow"
         android:scaleType="fitXY"
         android:scaleY="-1"

chrome/android/java/res/layout/keyboard_accessory_sheet.xml

@@ -22,7 +22,7 @@
     <ImageView
         android:id="@+id/accessory_sheet_shadow"
         android:layout_width="match_parent"
-        android:layout_height="@dimen/toolbar_shadow_height"
+        android:layout_height="@dimen/keyboard_accessory_shadow"
         android:src="@drawable/modern_toolbar_shadow"
         android:scaleType="fitXY"
         android:visibility="gone"

chrome/android/java/res/values/dimens.xml

@@ -130,9 +130,9 @@
     <dimen name="keyboard_accessory_action_padding">16dp</dimen>
     <dimen name="keyboard_accessory_half_padding">6dp</dimen>
     <dimen name="keyboard_accessory_height">48dp</dimen>
-    <dimen name="keyboard_accessory_height_with_shadow">50dp</dimen>
+    <dimen name="keyboard_accessory_height_with_shadow">56dp</dimen>
     <dimen name="keyboard_accessory_padding">6dp</dimen>
-    <dimen name="keyboard_accessory_shadow">2dp</dimen>
+    <dimen name="keyboard_accessory_shadow">5dp</dimen>
     <dimen name="keyboard_accessory_sheet_height">330dp</dimen>
     <dimen name="keyboard_accessory_suggestion_padding">16dp</dimen>
     <dimen name="keyboard_accessory_suggestion_height">48dp</dimen>