Fix/android voice call (#16180)

* fix(android): handle missing audio permission in voice calls

- Avoid stop errors when voice capture was never started
- Dispatch voice call error dialogs on the main thread
- Explain how to enable Audio capture on the Screen share page

Signed-off-by: fufesou <linlong1266@gmail.com>

* fix(android): restore audio after failed voice call switches

* fix: translations

Signed-off-by: fufesou <linlong1266@gmail.com>

* fix: translatin

Signed-off-by: fufesou <linlong1266@gmail.com>

* fix(i18n): match UI label capitalization in translated messages

Signed-off-by: fufesou <linlong1266@gmail.com>

---------

Signed-off-by: fufesou <linlong1266@gmail.com>
Co-authored-by: RustDesk <71636191+rustdesk@users.noreply.github.com>

src/lang/cn.rs

@@ -780,5 +780,6 @@ pub static ref T: std::collections::HashMap<&'static str, &'static str> =
         ("RustDesk could not load a GStreamer component needed for screen capture ({})", "RustDesk 无法加载屏幕捕获所需的 GStreamer 组件 ({})"),
         ("Relay fallback delay in seconds", "回落到中继前的等待时间（秒）"),
         ("relay-fallback-delay-tip", "已经建立的中继连接会等待直连的 WebRTC 多久，超过这个时间就改用中继。调大可以让较慢的直连有更多机会胜出；调小则在无法直连的网络上更快回落到中继。留空表示使用默认值 2.5 秒。"),
+        ("To start a voice call, enable \"Audio capture\" on the \"Screen share\" page.", "")
     ].iter().cloned().collect();
 }