Fix white background of the ActionBar

Which is problematic, since the text is white as well.

Just don't customize this: this way the ActionBar background is purple
in light mode, black in dark mode. Also, this way the dark mode
background is not exactly black, just some gray, similar to what other
apps do.

Related to <https://github.com/vmiklos/plees-tracker/issues/16>.

Tested-by: Travis

NEWS.adoc

@@ -1,5 +1,9 @@
 = Version descriptions
 
+== master
+
+- Resolves: gh#16 support dark mode (martiandolphin)
+
 == 6.2
 
 - Resolves: gh#15 export format is now better documented

app/src/main/res/values-night/colors.xml

@@ -4,5 +4,4 @@
     <color name="colorPrimary">#000</color>
     <color name="colorPrimaryDark">#000</color>
     <color name="colorAccent">#D81B60</color>
-    <color name="colorBackground">#000000</color>
 </resources>

app/src/main/res/values/colors.xml

@@ -4,7 +4,6 @@
     <color name="colorPrimary">#5E35B1</color>
     <color name="colorPrimaryDark">#5E35B1</color>
     <color name="colorAccent">#D81B60</color>
-    <color name="colorBackground">#ffffff</color>
 
 
     <!-- Dashboard  color-->

app/src/main/res/values/styles.xml

@@ -6,7 +6,6 @@
         <item name="colorPrimary">@color/colorPrimary</item>
         <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
         <item name="colorAccent">@color/colorAccent</item>
-        <item name="android:background">@color/colorBackground</item>
     </style>
 
 </resources>