feat(fs): resolve content URIs on Android (#1658)

* Implemented writeTextFile on Android.

* Added license headers.

* fix fmt checks.

* implement more file APIs

* change file

* cleanup

* refactor dialog plugin to leverage new FS APIs

* implement metadata functions

* fix build

* expose FS rust API

* resolve resources on android

* update pnpm

* update docs

---------

Co-authored-by: Lucas Nogueira <lucas@tauri.app>

plugins/fs/android/src/test/java/ExampleUnitTest.kt

@@ -0,0 +1,21 @@
+// Copyright 2019-2023 Tauri Programme within The Commons Conservancy
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-License-Identifier: MIT
+
+package com.plugin.fs
+
+import org.junit.Test
+
+import org.junit.Assert.*
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class ExampleUnitTest {
+    @Test
+    fun addition_isCorrect() {
+        assertEquals(4, 2 + 2)
+    }
+}