Remove unused react native lib, and ensure dependencies lib are explicitly declared

matrix-sdk-android-rx/build.gradle

@@ -33,7 +33,6 @@ android {
 }
 
 dependencies {
-    implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation project(":matrix-sdk-android")
     implementation 'androidx.appcompat:appcompat:1.1.0-beta01'
     implementation 'io.reactivex.rxjava2:rxkotlin:2.3.0'

matrix-sdk-android/build.gradle

@@ -94,7 +94,6 @@ dependencies {
     def markwon_version = '3.0.0'
     def daggerVersion = '2.23.1'
 
-    implementation fileTree(dir: 'libs', include: ['*.aar'])
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"