BUILD: upgrade to Gradle 7.0

- upgrade Kotlin to 1.4.32
- upgrade android gradle plugin to 4.1.3

- remove `versionNameSuffix`
- remove `buildToolsVersion` as android gradle plugin already done it
- remove unnecessary `targetCompatibility` and `sourceCompatibility` in subprojects
- remove proguard
- remove NeoTermBridgeExample
- remove unused tests
- remove bintray upload of NeoTermBridge

NeoLang/build.gradle

@@ -6,9 +6,6 @@ dependencies {
     compile rootProject.ext.deps["kotlin-stdlib"]
 }
 
-sourceCompatibility = "1.7"
-targetCompatibility = "1.7"
-
 buildscript {
     repositories {
         mavenCentral()
@@ -30,7 +27,6 @@ compileTestKotlin {
         jvmTarget = "1.8"
     }
 }
-
 dependencies {
     testImplementation rootProject.ext.deps["junit"]
 }