Messaging: Set input text box background

Fixes the background in dark mode. Also modify the color for light
mode to be a very light shade of the neutral color.

Change-Id: I8a420405dcc478f5d50bf9b1d4739a58f8cd976a

res/drawable/msg_bubble_input_rounded.xml

@@ -8,6 +8,6 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:shape="rectangle">
 
-    <solid android:color="@android:color/white" />
+    <solid android:color="@color/compose_send_text_background_color" />
     <corners android:radius="28dp" />
 </shape>

res/values-night/lineage_colors.xml

@@ -19,4 +19,6 @@
     <color name="lineage_accent">@*android:color/system_accent1_100</color>
 
     <color name="window_background">@*android:color/system_neutral1_900</color>
+
+    <color name="compose_send_text_background_color">@*android:color/system_neutral1_600</color>
 </resources>

res/values/lineage_colors.xml

@@ -24,4 +24,6 @@
 
     <color name="navigation_bar_bg">@*android:color/system_neutral1_10</color>
     <color name="navigation_bar_divider">@*android:color/system_neutral1_800</color>
+
+    <color name="compose_send_text_background_color">@*android:color/system_neutral1_50</color>
 </resources>