RNGP - Top level property enableHermes -> hermesEnabled

Summary:
This is part of a series of tasks to make the React Native Gradle Plugin (RNGP) variant-aware.

Here I'm renaming the top level property to enable hermes from `enableHermes` to `hermesEnabled`. We have a bunch of other properties which are called *Enabled. This one was following a different convention.

I'm retaining the backward compatibility for users using `project.ext.react.enableHermes` so this is not going to be a breakign change.

Changelog:
[Internal] [Changed] - RNGP - Top level property enableHermes -> hermesEnabled

Reviewed By: cipolleschi

Differential Revision: D40633109

fbshipit-source-id: 9d7efad6cb3bb382d1beb56966795a3f42bdaae6

Author: cortinico

packages/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/utils/ProjectUtils.kt

@@ -19,8 +19,8 @@ internal object ProjectUtils {
 
   internal val Project.isHermesEnabled: Boolean
     get() =
-        if (project.hasProperty("enableHermes")) {
-          project.property("enableHermes").toString().lowercase().toBooleanStrictOrNull() ?: true
+        if (project.hasProperty("hermesEnabled")) {
+          project.property("hermesEnabled").toString().lowercase().toBooleanStrictOrNull() ?: true
         } else if (project.extensions.extraProperties.has("react")) {
           @Suppress("UNCHECKED_CAST")
           val reactMap = project.extensions.extraProperties.get("react") as? Map<String, Any?>

packages/react-native-gradle-plugin/src/test/kotlin/com/facebook/react/utils/ProjectUtilsTest.kt

@@ -50,21 +50,21 @@ class ProjectUtilsTest {
   @Test
   fun isNewArchEnabled_withDisabledViaProperty_returnsFalse() {
     val project = createProject()
-    project.extensions.extraProperties.set("enableHermes", "false")
+    project.extensions.extraProperties.set("hermesEnabled", "false")
     assertFalse(project.isHermesEnabled)
   }
 
   @Test
   fun isHermesEnabled_withEnabledViaProperty_returnsTrue() {
     val project = createProject()
-    project.extensions.extraProperties.set("enableHermes", "true")
+    project.extensions.extraProperties.set("hermesEnabled", "true")
     assertTrue(project.isHermesEnabled)
   }
 
   @Test
   fun isHermesEnabled_withInvalidViaProperty_returnsTrue() {
     val project = createProject()
-    project.extensions.extraProperties.set("enableHermes", "¯\\_(ツ)_/¯")
+    project.extensions.extraProperties.set("hermesEnabled", "¯\\_(ツ)_/¯")
     assertTrue(project.isHermesEnabled)
   }
 

packages/rn-tester/android/app/gradle.properties

@@ -14,3 +14,5 @@ FLIPPER_VERSION=0.125.0
 
 # RN-Tester is building with NewArch always enabled
 newArchEnabled=true
+# RN-Tester is running with Hermes enabled and filtering variants with enableHermesOnlyInVariants
+hermesEnabled=true