Use Dagger Hilt for dependency injection

This gets rid of our own janky dependency injection through the AegisApplication class

app/src/main/java/com/beemdevelopment/aegis/AegisModule.java

@@ -0,0 +1,35 @@
+package com.beemdevelopment.aegis;
+
+import android.content.Context;
+
+import com.beemdevelopment.aegis.icons.IconPackManager;
+import com.beemdevelopment.aegis.vault.VaultManager;
+
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+import dagger.hilt.InstallIn;
+import dagger.hilt.android.qualifiers.ApplicationContext;
+import dagger.hilt.components.SingletonComponent;
+
+@Module
+@InstallIn(SingletonComponent.class)
+public class AegisModule {
+    @Provides
+    @Singleton
+    public static IconPackManager provideIconPackManager(@ApplicationContext Context context) {
+        return new IconPackManager(context);
+    }
+
+    @Provides
+    @Singleton
+    public static VaultManager provideVaultManager(@ApplicationContext Context context) {
+        return new VaultManager(context);
+    }
+
+    @Provides
+    public static Preferences providePreferences(@ApplicationContext Context context) {
+        return new Preferences(context);
+    }
+}