make TermuxService (com.termux.service_execute) available to other apps #804
Description
So, any app can use the TermuxService execute.
Only minor changes in AndroidManifest.xml are needed:
```
< permission android:name="com.termux.app.TermuxService">
< /permission>
<service android:name="com.termux.app.TermuxService" android:permission="com.termux.app.TermuxService">
<intent-filter>
<action android:name="com.termux.service_execute" />
</intent-filter>
</service>