Specify correct ndk version (#172)

Addresses the errors seen in DefinedNet/mobile_nebula/actions/runs/11221064890/job/31190581077#step:13:1260

Locally I am able to perform most of a release build after removing these proguard rules which were previously added to avoid minification stripping out flutter code. That seems to no longer be required, though.

.github/workflows/release.yml

@@ -26,14 +26,6 @@ jobs:
         with:
           flutter-version: '3.24.1'
 
-      - uses: nttld/setup-ndk@v1
-        id: setup-ndk
-        with:
-          ndk-version: r21b
-          # r21b is 21.1.6352462, if it is not published here https://developer.android.com/ndk/downloads
-          # or here https://github.com/android/ndk/wiki/Unsupported-Downloads then you must download them and look at
-          # source.properties to determine the version
-
       - name: Check out code
         uses: actions/checkout@v3
 
@@ -112,7 +104,6 @@ jobs:
       - name: Build Android
         env:
           TOKEN: ${{ secrets.MACHINE_USER_PAT }}
-          ANDROID_NDK_HOME: ${{ steps.setup-ndk.outputs.ndk-path }}
           GOOGLE_PLAY_KEYSTORE_PASSWORD: ${{ secrets.GOOGLE_PLAY_KEYSTORE_PASSWORD }}
         run: |
           flutter build appbundle --build-number="$BUILD_NUMBER" --build-name="$BUILD_NAME"

android/app/build.gradle

@@ -28,6 +28,9 @@ android {
 
     compileSdkVersion 34
 
+    // default ndk version for AGP 8.5: https://developer.android.com/build/releases/past-releases/agp-8-5-0-release-notes
+    ndkVersion "26.1.10909125"
+
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
     }

android/app/proguard-rules.pro

@@ -1,11 +1,3 @@
-# Flutter Wrapper - this came from guidance at https://medium.com/@swav.kulinski/flutter-and-android-obfuscation-8768ac544421
--keep class io.flutter.app.** { *; }
--keep class io.flutter.plugin.**  { *; }
--keep class io.flutter.util.**  { *; }
--keep class io.flutter.view.**  { *; }
--keep class io.flutter.**  { *; }
--keep class io.flutter.plugins.**  { *; }
-
 # Keep our class names for gson
 -keep class net.defined.mobile_nebula.** { *; }
 -keep class androidx.security.crypto.** { *; }

nebula/Makefile

@@ -7,7 +7,7 @@ clean:
 
 mobileNebula.aar: *.go go.sum
 	go get -d golang.org/x/mobile/cmd/gomobile
-	gomobile bind -trimpath -v --target=android
+	gomobile bind -trimpath -v --target=android -androidapi 26
 
 MobileNebula.xcframework: *.go go.sum
 	go get -d golang.org/x/mobile/cmd/gomobile