App icon: be complaint with Android requirements. (#253)

Fixes #121.

build.gradle

@@ -60,7 +60,7 @@ android {
     defaultConfig {
         applicationId "de.dennisguse.opentracks"
         manifestPlaceholders = [
-                applicationLogo: "@drawable/ic_logo_color_24dp",
+                applicationLogo: "@mipmap/ic_launcher",
                 applicationName: "@string/app_name"
         ]
 
@@ -83,7 +83,7 @@ android {
             applicationIdSuffix ".debug"
             versionNameSuffix "-debug"
             manifestPlaceholders = [
-                    applicationLogo: "@drawable/ic_logo_black_24dp",
+                    applicationLogo: "@mipmap/ic_launcher_debug",
                     applicationName: "OpenTracks (Debug)"
             ]
         }

src/main/res/drawable/ic_logo_black_24dp.xml

@@ -1,9 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="24dp"
-    android:height="24dp"
-    android:viewportWidth="100"
-    android:viewportHeight="100">
-    <path
-        android:fillColor="#000000"
-        android:pathData="M82.489,12.834C83.196,10.418 82.043,9.556 79.926,10.917L10.087,55.828c-2.117,1.361 -1.795,2.628 0.714,2.815L39.806,60.807c2.51,0.188 5.291,2.267 6.18,4.621l10.282,27.208c0.89,2.354 2.195,2.304 2.902,-0.111z" />
-</vector>

src/main/res/drawable/ic_logo_color_108dp.xml

@@ -0,0 +1,24 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+  <path android:pathData="M69.997,34.926C70.383,33.606 69.753,33.134 68.596,33.878L30.427,58.424c-1.157,0.744 -0.981,1.436 0.39,1.538L46.669,61.145c1.372,0.103 2.892,1.239 3.378,2.526l5.619,14.87c0.486,1.287 1.2,1.259 1.586,-0.061z">
+    <aapt:attr name="android:fillColor">
+      <gradient
+          android:startY="73.51573"
+          android:startX="40.05078"
+          android:endY="34.035606"
+          android:endX="69.58224"
+          android:type="linear">
+        <item
+            android:offset="0"
+            android:color="#FFFBB22F" />
+        <item
+            android:offset="1"
+            android:color="#FFF58820" />
+      </gradient>
+    </aapt:attr>
+  </path>
+</vector>

src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@color/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_logo_color_108dp" />
+</adaptive-icon>

src/main/res/mipmap-anydpi-v26/ic_launcher_debug.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@color/ic_launcher_debug_background" />
+    <foreground android:drawable="@drawable/ic_logo_color_108dp" />
+</adaptive-icon>

src/main/res/values/ic_launcher_background.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="ic_launcher_background">#FFFFFF</color>
+</resources>

src/main/res/values/ic_launcher_debug_background.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="ic_launcher_debug_background">#8F0000</color>
+</resources>