android: derive versionCode from tailscale version (#807)

Previously, versionCode was only set by the Play Store builder and never committed back to the repo, so fdroid wouldn't detect updates.
Now, we compute versionCode deterministically using the formula major*100M + minor*100K + patch*10 + platform, so that fdroid and Play Store builds always produce the same value.

Updates tailscale/tailscale#18969

Signed-off-by: kari-ts <kari@tailscale.com>

Author: kari-ts

Makefile

@@ -151,7 +151,7 @@ $(RELEASE_AAB): version gradle-dependencies
 
 $(RELEASE_TV_AAB): version gradle-dependencies
 	@echo "Building TV release AAB"
-	(cd android && ./gradlew test bundleRelease_tv)
+	(cd android && ./gradlew test bundleTvRelease -PPLATFORM=1) 
 	install -C ./android/build/outputs/bundle/release_tv/android-release_tv.aab $@
 
 tailscale-test.apk: version gradle-dependencies
@@ -279,10 +279,6 @@ bumposs: update-oss tailscale.version
 	source tailscale.version && git commit -sm "android: bump OSS" -m "OSS and Version updated to $${VERSION_LONG}" go.toolchain.rev android/build.gradle go.mod go.sum
 	source tailscale.version && git tag -a "$${VERSION_LONG}" -m "OSS and Version updated to $${VERSION_LONG}"
 
-.PHONY: bump_version_code ## Bump the version code in build.gradle
-bump_version_code:
-	sed -i'.bak' "s/versionCode .*/versionCode $$(expr $$(awk '/versionCode ([0-9]+)/{print $$2}' android/build.gradle) + 1)/" android/build.gradle && rm android/build.gradle.bak
-
 .PHONY: update-oss ## Update the tailscale.com go module
 update-oss:
 	curl -f https://raw.githubusercontent.com/tailscale/tailscale/refs/heads/main/go.toolchain.rev > go.toolchain.rev.new

android/build.gradle

@@ -37,7 +37,7 @@ android {
     defaultConfig {
         minSdkVersion 26
         targetSdkVersion 35
-        versionCode 615
+        versionCode computeVersionCode()
         versionName getVersionProperty("VERSION_LONG")
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
 
@@ -195,3 +195,15 @@ def getVersionProperty(key) {
     versionProps.load(project.file('../tailscale.version').newDataInputStream())
     return versionProps.getProperty(key).replaceAll('^\"|\"$', '')
 }
+
+def computeVersionCode() {
+    def versionProps = new Properties()
+    versionProps.load(project.file('../tailscale.version').newDataInputStream())
+    
+    def major = versionProps.getProperty('VERSION_MAJOR') as int
+    def minor = versionProps.getProperty('VERSION_MINOR') as int
+    def patch = versionProps.getProperty('VERSION_PATCH') as int
+    def platform = (project.findProperty('PLATFORM') ?: '0') as int
+    
+    return major * 100000000 + minor * 100000 + patch * 10 + platform
+}          

docker/DockerFile.amd64-build

@@ -43,4 +43,4 @@ RUN chmod 755 android/gradlew && \
     ./android/gradlew
 
 # Build the android app, bump the playstore version code, and make the tv release
-CMD make clean && make release && make bump_version_code && make release-tv
+CMD make clean && make release && make release-tv