Add emacsclient desktop file equivalent on Android

* doc/emacs/android.texi (Android File System):
* java/AndroidManifest.xml.in: Update with new activity.  Remove
Android 10 restrictions through a special flag.

* java/org/gnu/emacs/EmacsNative.java (getProcName): New
function.
* java/org/gnu/emacs/EmacsOpenActivity.java (EmacsOpenActivity):
New file.
* java/org/gnu/emacs/EmacsService.java (getLibraryDirection):
Remove unused annotation.
* lib-src/emacsclient.c (decode_options): Set alt_display on
Android.
* src/android.c (android_proc_name): New function.
(NATIVE_NAME): Export via JNI.

java/AndroidManifest.xml.in

@@ -24,6 +24,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>. -->
 	  package="org.gnu.emacs"
 	  android:targetSandboxVersion="1"
 	  android:installLocation="auto"
+	  android:requestLegacyExternalStorage="true"
 	  android:versionCode="@emacs_major_version@"
 	  android:versionName="@version@">
 
@@ -82,6 +83,84 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>. -->
       </intent-filter>
     </activity>
 
+    <activity android:name="org.gnu.emacs.EmacsOpenActivity"
+	      android:exported="true">
+
+      <!-- Allow Emacs to open all kinds of files known to Android.  -->
+
+      <intent-filter>
+        <action android:name="android.intent.action.VIEW"/>
+	<action android:name="android.intent.action.EDIT"/>
+	<action android:name="android.intent.action.PICK"/>
+
+        <category android:name="android.intent.category.DEFAULT"/>
+
+	<data android:mimeType="image/aces"/>
+	<data android:mimeType="image/avci"/>
+	<data android:mimeType="image/avcs"/>
+	<data android:mimeType="image/avif"/>
+	<data android:mimeType="image/bmp"/>
+	<data android:mimeType="image/cgm"/>
+	<data android:mimeType="image/dicom-rle"/>
+	<data android:mimeType="image/dpx"/>
+	<data android:mimeType="image/emf"/>
+	<data android:mimeType="image/example"/>
+	<data android:mimeType="image/fits"/>
+	<data android:mimeType="image/g3fax"/>
+	<data android:mimeType="image/heic"/>
+	<data android:mimeType="image/heic-sequence"/>
+	<data android:mimeType="image/heif"/>
+	<data android:mimeType="image/heif-sequence"/>
+	<data android:mimeType="image/hej2k"/>
+	<data android:mimeType="image/hsj2"/>
+	<data android:mimeType="image/jls"/>
+	<data android:mimeType="image/jp2"/>
+	<data android:mimeType="image/jph"/>
+	<data android:mimeType="image/jphc"/>
+	<data android:mimeType="image/jpm"/>
+	<data android:mimeType="image/jpx"/>
+	<data android:mimeType="image/jxr"/>
+	<data android:mimeType="image/jxrA"/>
+	<data android:mimeType="image/jxrS"/>
+	<data android:mimeType="image/jxs"/>
+	<data android:mimeType="image/jxsc"/>
+	<data android:mimeType="image/jxsi"/>
+	<data android:mimeType="image/jxss"/>
+	<data android:mimeType="image/ktx"/>
+	<data android:mimeType="image/ktx2"/>
+	<data android:mimeType="image/naplps"/>
+	<data android:mimeType="image/png"/>
+	<data android:mimeType="image/prs.btif"/>
+	<data android:mimeType="image/prs.pti"/>
+	<data android:mimeType="image/pwg-raster"/>
+	<data android:mimeType="image/svg+xml"/>
+	<data android:mimeType="image/t38"/>
+	<data android:mimeType="image/tiff"/>
+	<data android:mimeType="image/tiff-fx"/>
+	<data android:mimeType="text/*"/>
+        <data android:mimeType="application/*xml"/>
+        <data android:mimeType="application/atom+xml"/>
+        <data android:mimeType="application/dxf"/>
+        <data android:mimeType="application/ecmascript"/>
+        <data android:mimeType="application/javascript"/>
+        <data android:mimeType="application/json"/>
+        <data android:mimeType="application/*log*"/>
+        <data android:mimeType="application/octet-stream"/>
+        <data android:mimeType="application/soap+xm"/>
+        <data android:mimeType="application/x-caramel"/>
+        <data android:mimeType="application/x-klaunch"/>
+        <data android:mimeType="application/x-latex"/>
+        <data android:mimeType="application/x-sh"/>
+        <data android:mimeType="application/x-tcl"/>
+        <data android:mimeType="application/x-tex*"/>
+        <data android:mimeType="application/x-troff*"/>
+        <data android:mimeType="application/xhtml+xml"/>
+        <data android:mimeType="application/xml*"/>
+        <data android:mimeType="application/zip"/>
+        <data android:mimeType="application/x-zip-compressed"/>
+      </intent-filter>
+    </activity>
+
     <activity android:name="org.gnu.emacs.EmacsMultitaskActivity"
 	      android:windowSoftInputMode="adjustResize"
 	      android:exported="true"