chore: remove unused gitHash function and update AS requirements due to AGP 9.1.0 upgrade (#221)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->

## Summary by CodeRabbit

* **Documentation**
  * Updated minimum Android Studio version requirement to Panda 2 (2025.3.2) or later.

* **Chores**
  * Removed unused git hash generation from the build process.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: Manabu-GT

CONTRIBUTING.md

@@ -12,7 +12,7 @@ Thank you for considering contributing to DebugOverlay! This document outlines h
 
 ### Prerequisites
 
-- Android Studio Narwhal (2025.1.1) or later
+- Android Studio Panda 2 (2025.3.2) or later
 - JDK 21+
 - Kotlin 2.2+
 - Basic knowledge of Jetpack Compose

sample/build.gradle.kts

@@ -14,14 +14,6 @@ java {
   }
 }
 
-fun gitHash(): String = Runtime
-  .getRuntime()
-  .exec("git rev-parse --short HEAD")
-  .inputStream
-  .bufferedReader()
-  .readText()
-  .trim()
-
 android {
   namespace = "com.ms.square.debugoverlay.sample"
   compileSdk = libs.versions.androidCompileSdk.get().toInt()
@@ -33,8 +25,6 @@ android {
 
     versionCode = 1
     versionName = "1.0.0"
-
-    buildConfigField("String", "GIT_HASH", "\"${gitHash()}\"")
   }
 
   signingConfigs {