Upgrade Kotlin to 1.8.20 (#4753)

Summary:
[android] Upgrade Kotlin to 1.8.20
The additional source/target settings should hopefully no longer be necessary with
AGP 8.1:

https://kotlinlang.org/docs/gradle-configure-project.html#gradle-java-toolchains-support

Pull Request resolved: https://github.com/facebook/flipper/pull/4753

Test Plan:
- CI
- Build sample app
- AS sync

 ---
Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/flipper/pull/4753).
* https://github.com/facebook/flipper/issues/4759
* https://github.com/facebook/flipper/issues/4758
* https://github.com/facebook/flipper/issues/4757
* https://github.com/facebook/flipper/issues/4756
* https://github.com/facebook/flipper/issues/4755
* https://github.com/facebook/flipper/issues/4754
* __->__ https://github.com/facebook/flipper/issues/4753
* https://github.com/facebook/flipper/issues/4752
* https://github.com/facebook/flipper/issues/4751

Reviewed By: ivanmisuno

Differential Revision: D46068906

Pulled By: passy

fbshipit-source-id: 93da60ebfe2ec590ef88ea1936fcfd5257699cc7

android/tutorial/build.gradle

@@ -22,8 +22,8 @@ android {
     }
 
     compileOptions {
-        targetCompatibility JavaVersion.VERSION_1_8
-        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility rootProject.javaTargetVersion
+        sourceCompatibility rootProject.javaTargetVersion
     }
 
     buildTypes {
@@ -33,10 +33,6 @@ android {
         }
     }
 
-    kotlinOptions {
-        jvmTarget = "1.8"
-    }
-
     packagingOptions {
         pickFirst "**/libcrypto.so"
         pickFirst "**/libevent-2.1.so"