WIP make things compile

libsession/build.gradle

@@ -1,12 +1,11 @@
 plugins {
     id 'com.android.library'
     id 'kotlin-android'
-    id "org.jetbrains.kotlin.kapt"
 }
 
 android {
     compileSdkVersion 30
-    buildToolsVersion "30.0.1"
+    buildToolsVersion '29.0.3'
 
     defaultConfig {
         minSdkVersion 21

libsession/src/main/java/org/session/libsession/utilities/TextSecurePreferences.kt

@@ -963,6 +963,7 @@ object TextSecurePreferences {
         return getStringPreference(context, THREAD_TRIM_LENGTH, "500")!!.toInt()
     }
 
+    @JvmStatic
     fun isSystemEmojiPreferred(context: Context): Boolean {
         return getBooleanPreference(context, SYSTEM_EMOJI_PREF, false)
     }

libsession/src/main/java/org/session/libsession/utilities/Util.kt

@@ -269,4 +269,9 @@ object Util {
         return ""
     }
 
+    @JvmStatic
+    fun isEmpty(collection: Collection<*>?): Boolean {
+        return collection == null || collection.isEmpty()
+    }
+
 }