add a new flavor, show Donate button in F-droids About section

app/build.gradle

@@ -33,7 +33,7 @@ android {
 
     buildTypes {
         debug {
-	        applicationIdSuffix ".debug"
+            applicationIdSuffix ".debug"
         }
         release {
             minifyEnabled true
@@ -44,6 +44,12 @@ android {
         }
     }
 
+    flavorDimensions "variants"
+    productFlavors {
+        core {}
+        fdroid {}
+    }
+
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
     }
@@ -55,7 +61,7 @@ android {
 }
 
 dependencies {
-    implementation 'com.github.SimpleMobileTools:Simple-Commons:14033f9b50'
+    implementation 'com.github.SimpleMobileTools:Simple-Commons:02b48c0b4d'
     implementation 'me.grantland:autofittextview:0.2.1'
     implementation 'net.objecthunter:exp4j:0.4.8'
 }

app/src/fdroid/res/values/bools.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <bool name="default_vibrate_on_press">true</bool>
+    <bool name="show_donate_in_about">true</bool>
+</resources>