Replaced some more .png icons with vector assets

uhabits-android/src/main/res/drawable/ic_action_check.xml

@@ -0,0 +1,5 @@
+<vector android:height="32dp" android:tint="#373839"
+    android:viewportHeight="24" android:viewportWidth="24"
+    android:width="32dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="@android:color/white" android:pathData="M9,16.17L4.83,12l-1.42,1.41L9,19 21,7l-1.41,-1.41z"/>
+</vector>

uhabits-android/src/main/res/drawable/ic_action_color_dark.xml

@@ -0,0 +1,14 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="32dp"
+    android:height="32dp"
+    android:tint="#D9D9D9"
+    android:viewportWidth="32"
+    android:viewportHeight="32">
+    <group
+        android:translateX="4"
+        android:translateY="4">
+        <path
+            android:fillColor="@android:color/white"
+            android:pathData="M12,3c-4.97,0 -9,4.03 -9,9s4.03,9 9,9c0.83,0 1.5,-0.67 1.5,-1.5 0,-0.39 -0.15,-0.74 -0.39,-1.01 -0.23,-0.26 -0.38,-0.61 -0.38,-0.99 0,-0.83 0.67,-1.5 1.5,-1.5L16,16c2.76,0 5,-2.24 5,-5 0,-4.42 -4.03,-8 -9,-8zM6.5,12c-0.83,0 -1.5,-0.67 -1.5,-1.5S5.67,9 6.5,9 8,9.67 8,10.5 7.33,12 6.5,12zM9.5,8C8.67,8 8,7.33 8,6.5S8.67,5 9.5,5s1.5,0.67 1.5,1.5S10.33,8 9.5,8zM14.5,8c-0.83,0 -1.5,-0.67 -1.5,-1.5S13.67,5 14.5,5s1.5,0.67 1.5,1.5S15.33,8 14.5,8zM17.5,12c-0.83,0 -1.5,-0.67 -1.5,-1.5S16.67,9 17.5,9s1.5,0.67 1.5,1.5 -0.67,1.5 -1.5,1.5z" />
+    </group>
+</vector>

uhabits-android/src/main/res/drawable/ic_action_color_light.xml

@@ -0,0 +1,14 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="32dp"
+    android:height="32dp"
+    android:tint="#373839"
+    android:viewportWidth="32"
+    android:viewportHeight="32">
+    <group
+        android:translateX="4"
+        android:translateY="4">
+        <path
+            android:fillColor="@android:color/white"
+            android:pathData="M12,3c-4.97,0 -9,4.03 -9,9s4.03,9 9,9c0.83,0 1.5,-0.67 1.5,-1.5 0,-0.39 -0.15,-0.74 -0.39,-1.01 -0.23,-0.26 -0.38,-0.61 -0.38,-0.99 0,-0.83 0.67,-1.5 1.5,-1.5L16,16c2.76,0 5,-2.24 5,-5 0,-4.42 -4.03,-8 -9,-8zM6.5,12c-0.83,0 -1.5,-0.67 -1.5,-1.5S5.67,9 6.5,9 8,9.67 8,10.5 7.33,12 6.5,12zM9.5,8C8.67,8 8,7.33 8,6.5S8.67,5 9.5,5s1.5,0.67 1.5,1.5S10.33,8 9.5,8zM14.5,8c-0.83,0 -1.5,-0.67 -1.5,-1.5S13.67,5 14.5,5s1.5,0.67 1.5,1.5S15.33,8 14.5,8zM17.5,12c-0.83,0 -1.5,-0.67 -1.5,-1.5S16.67,9 17.5,9s1.5,0.67 1.5,1.5 -0.67,1.5 -1.5,1.5z" />
+    </group>
+</vector>

uhabits-android/src/main/res/drawable/ic_action_download_dark.xml

@@ -0,0 +1,14 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="32dp"
+    android:height="32dp"
+    android:tint="#D9D9D9"
+    android:viewportWidth="32"
+    android:viewportHeight="32">
+    <group
+        android:translateX="4"
+        android:translateY="4">
+        <path
+            android:fillColor="@android:color/white"
+            android:pathData="M19,9h-4V3H9v6H5l7,7 7,-7zM5,18v2h14v-2H5z" />
+    </group>
+</vector>