Added Nordic DFU library to dependencies

app/build.gradle

@@ -75,6 +75,7 @@ dependencies {
     implementation "androidx.gridlayout:gridlayout:1.0.0"
     implementation "com.google.android.material:material:1.1.0"
     implementation "androidx.palette:palette:1.0.0"
+    implementation "no.nordicsemi.android:dfu:1.11.0"
     implementation("com.github.tony19:logback-android-classic:1.1.1-6") {
         exclude group: "com.google.android", module: "android"
     }

app/proguard-rules.pro

@@ -35,8 +35,12 @@
 
 -keep class **$Properties { *; }
 
+# Keep database migration classes accessed trough reflection
 -keep class **.gadgetbridge.database.schema.* { *; }
 
+# Keep Nordic DFU library
+-keep class no.nordicsemi.android.dfu.** { *; }
+
 # Keep dependency android-emojify (io.wax911.emojify) uses
 -keep class org.hamcrest.** { *; }