Fix navigation bar icon contrast on API in [21,27[ (#1342)

CHANGES.md

@@ -13,6 +13,7 @@ Bugfix 🐛:
  - Switch theme is not fully taken into account without restarting the app
  - Temporary fix to show error when user is creating an account on matrix.org with userId containing only digits (#1410)
  - Reply composer overlay stays on screen too long after send (#1169)
+ - Fix navigation bar icon contrast on API in [21,27[ (#1342)
 
 Translations 🗣:
  -

vector/src/main/res/values-v21/theme_light.xml

@@ -3,7 +3,8 @@
 
     <style name="AppTheme.Light.v21" parent="AppTheme.Base.Light">
         <item name="android:statusBarColor">@color/riotx_header_panel_background_light</item>
-        <item name="android:navigationBarColor">@color/riotx_header_panel_background_light</item>
+        <!-- Use dark color, to have enough contrast with icons color. windowLightNavigationBar is only available in API 27+ -->
+        <item name="android:navigationBarColor">@color/riotx_header_panel_background_dark</item>
 
         <!-- enable window content transitions -->
         <item name="android:windowContentTransitions">true</item>

vector/src/main/res/values-v21/theme_status.xml

@@ -3,7 +3,8 @@
 
     <style name="AppTheme.Status.v21" parent="AppTheme.Base.Status">
         <item name="android:statusBarColor">@color/riotx_header_panel_background_light</item>
-        <item name="android:navigationBarColor">@color/riotx_header_panel_background_light</item>
+        <!-- Use dark color, to have enough contrast with icons color. windowLightNavigationBar is only available in API 27+ -->
+        <item name="android:navigationBarColor">@color/riotx_header_panel_background_dark</item>
 
         <!-- enable window content transitions -->
         <item name="android:windowContentTransitions">true</item>

vector/src/main/res/values-v27/theme_light.xml

@@ -2,6 +2,7 @@
 <resources>
 
     <style name="AppTheme.Light.v27" parent="AppTheme.Light.v23">
+        <item name="android:navigationBarColor">@color/riotx_header_panel_background_light</item>
         <item name="android:windowLightNavigationBar">true</item>
     </style>
 

vector/src/main/res/values-v27/theme_status.xml

@@ -2,6 +2,7 @@
 <resources>
 
     <style name="AppTheme.Status.v27" parent="AppTheme.Status.v23">
+        <item name="android:navigationBarColor">@color/riotx_header_panel_background_light</item>
         <item name="android:windowLightNavigationBar">true</item>
     </style>