[Android] Use Hermes V1 by default

Author: cipolleschi

build.gradle.kts

@@ -137,7 +137,13 @@ if (project.findProperty("react.internal.useHermesStable")?.toString()?.toBoolea
     )
   }
 
-  hermesSubstitution = "$hermesCompilerVersion-SNAPSHOT" to "Users opted to use hermes nightly"
+  val hermesV1Enabled =
+      project.findProperty("hermesV1Enabled")?.toString()?.toBoolean() ?: true
+  // Hermes V1 stable releases are published without the -SNAPSHOT suffix.
+  // Legacy nightly builds use -SNAPSHOT.
+  val resolvedVersion =
+      if (hermesV1Enabled) hermesCompilerVersion else "$hermesCompilerVersion-SNAPSHOT"
+  hermesSubstitution = resolvedVersion to "Users opted to use hermes nightly"
 } else {
   logger.warn(
       """

packages/react-native/sdks/hermes-engine/version.properties

@@ -1,2 +1,2 @@
 HERMES_VERSION_NAME=1000.0.0
-HERMES_V1_VERSION_NAME=250829098.0.11
+HERMES_V1_VERSION_NAME=250829098.0.12

scripts/try-set-nightly-hermes-compiler.js

@@ -16,10 +16,10 @@ function main() {
  const hermesCompilerVersion = packageJson.dependencies['hermes-compiler'];
 
  if (hermesCompilerVersion === '0.0.0') {
-   console.log(`Hermes compiler version not set. Updating to the latest nightly release.`);
-   execSync('yarn workspace react-native add hermes-compiler@nightly --exact', { stdio: 'inherit' });
+   console.log(`Hermes compiler version not set. Updating to the latest-v1 release.`);
+   execSync('yarn workspace react-native add hermes-compiler@latest-v1 --exact', { stdio: 'inherit' });
  } else {
-   console.log(`Hermes compiler version set to ${hermesCompilerVersion}. Not setting nightly hermes.`);
+   console.log(`Hermes compiler version set to ${hermesCompilerVersion}. Not setting hermes.`);
  }
 }