passgo package: modernize for go 1.24; reset store.Empty in GetStore.

- Update to //go:build tags, gofmt, and the android-35 javac template
  in //go:generate.
- GetStore: reset store.Empty when the store directory exists (it was
  only set true when the dir was missing, so a reconfigured store kept
  the stale 'Empty' state and showed the configure button).
- Rebuild PgpConnect.jar (android-35).

impl_android.go

@@ -1,6 +1,8 @@
+//go:build android
 // +build android
+
 //go:generate mkdir -p classes
-//go:generate javac -bootclasspath $ANDROID_HOME/platforms/android-29/android.jar -classpath openpgp-api.jar -d classes PgpConnect.java Foo.java
+//go:generate javac -nowarn -classpath $ANDROID_HOME/platforms/android-35/android.jar:openpgp-api.jar -d classes PgpConnect.java
 //go:generate jar cf PgpConnect.jar -C classes .
 //go:generate rm -rf classes
 
@@ -15,8 +17,8 @@ import "C"
 import (
 	"fmt"
 	"io/ioutil"
-	"path"
 	"log"
+	"path"
 	"strings"
 	"sync"
 	"unsafe"

impl_darwin.go

@@ -1,3 +1,4 @@
+//go:build darwin
 // +build darwin
 
 package passgo

impl_linux.go

@@ -1,3 +1,4 @@
+//go:build !android && linux
 // +build !android,linux
 
 package passgo

impl_shared.go

@@ -1,3 +1,4 @@
+//go:build darwin || (!android && linux)
 // +build darwin !android,linux
 
 package passgo

jni_android.go

@@ -13,11 +13,12 @@ import (
 	"fmt"
 	"log"
 	"runtime"
-	"unsafe"
 	"sync"
+	"unsafe"
 )
 
 var theJVM *C.JavaVM
+
 type JNIEnv = C.JNIEnv
 
 func SetJVM(jvm uintptr) {

main.go

@@ -49,6 +49,8 @@ func GetStore(store *Store) error {
 	}
 	if _, err := os.Stat(store.Dir); os.IsNotExist(err) {
 		store.Empty = true
+	} else {
+		store.Empty = false
 	}
 	id, err := ioutil.ReadFile(path.Join(store.Dir, ".gpg-id"))
 	if err != nil {