Downgrade lib version for PDFReader project

PDFReaderReaderModule

@@ -1 +1 @@
-Subproject commit e6107fa676f60197d6eb054b059fd32d6d372b62
+Subproject commit e621f24f68744918e95e86d57139f180d742b543

app/build.gradle

@@ -5,11 +5,11 @@ apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 27
     defaultConfig {
         applicationId "com.kdanmobile.testpdflib"
         minSdkVersion 15
-        targetSdkVersion 28
+        targetSdkVersion 27
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -30,11 +30,11 @@ android {
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    implementation 'com.android.support:appcompat-v7:28.0.0'
-    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
-    implementation 'com.android.support:recyclerview-v7:28.0.0'
+    implementation 'com.android.support:appcompat-v7:27.1.1'
+    implementation 'com.android.support:recyclerview-v7:27.1.1'
+    implementation 'com.android.support.constraint:constraint-layout:1.1.2'
     testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'com.android.support.test:runner:1.0.2'
+    androidTestImplementation 'com.android.support.test:runner:0.5'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
 
     implementation project(':PDFReaderReaderModule')

build.gradle

@@ -1,13 +1,13 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    ext.kotlin_version = '1.3.10'
+    ext.kotlin_version = '1.2.51'
     repositories {
         google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.2.0'
+        classpath 'com.android.tools.build:gradle:3.2.1'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong