Updated compatibility version to java 1.8

app/build.gradle.kts

@@ -29,11 +29,15 @@ android {
             applicationIdSuffix = ".debug"
         }
     }
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_1_8
+        targetCompatibility = JavaVersion.VERSION_1_8
+    }
 }
 
 dependencies {
     // kotlin standard library
-    implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.72")
+    implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.72")
 
     // androidx libraries
     implementation("androidx.appcompat:appcompat:1.1.0")