android: fs: Fix Exists / IsFile for SAF.

src/android/app/src/main/java/org/yuzu/yuzu_emu/NativeLibrary.kt

@@ -19,6 +19,8 @@ import org.yuzu.yuzu_emu.activities.EmulationActivity
 import org.yuzu.yuzu_emu.utils.DocumentsTree.Companion.isNativePath
 import org.yuzu.yuzu_emu.utils.FileUtil.getFileSize
 import org.yuzu.yuzu_emu.utils.FileUtil.openContentUri
+import org.yuzu.yuzu_emu.utils.FileUtil.exists
+import org.yuzu.yuzu_emu.utils.FileUtil.isDirectory
 import org.yuzu.yuzu_emu.utils.Log.error
 import org.yuzu.yuzu_emu.utils.Log.verbose
 import org.yuzu.yuzu_emu.utils.Log.warning
@@ -85,6 +87,22 @@ object NativeLibrary {
         } else getFileSize(appContext, path)
     }
 
+    @Keep
+    @JvmStatic
+    fun exists(path: String?): Boolean {
+        return if (isNativePath(path!!)) {
+            YuzuApplication.documentsTree!!.exists(path)
+        } else exists(appContext, path)
+    }
+
+    @Keep
+    @JvmStatic
+    fun isDirectory(path: String?): Boolean {
+        return if (isNativePath(path!!)) {
+            YuzuApplication.documentsTree!!.isDirectory(path)
+        } else isDirectory(appContext, path)
+    }
+
     /**
      * Returns true if pro controller isn't available and handheld is
      */

src/android/app/src/main/java/org/yuzu/yuzu_emu/utils/DocumentsTree.kt

@@ -36,6 +36,11 @@ class DocumentsTree {
         return resolvePath(filepath) != null
     }
 
+    fun isDirectory(filepath: String): Boolean {
+        val node = resolvePath(filepath)
+        return node != null && node.isDirectory
+    }
+
     private fun resolvePath(filepath: String): DocumentsNode? {
         val tokens = StringTokenizer(filepath, File.separator, false)
         var iterator = root