Android: Somewhat align scancode conversions with Firefox

Firefox' source at:
https://searchfox.org/mozilla-central/rev/c597e9c789ad36af84a0370d395be066b7dc94f4/widget/NativeKeyToDOMCodeName.h

Seems to use some other form of scan code? So instead we try to map as
many of the codes available on `Keycode` that they do as possible.

src/changelog/unreleased.md

@@ -75,6 +75,7 @@ changelog entry.
   variables to test the respective modifiers of window creation.
 - Added `Window::surface_position`, which is the position of the surface inside the window.
 - Added `Window::safe_area`, which describes the area of the surface that is unobstructed.
+- On Android, improved scancode conversions for more obscure key codes.
 
 ### Changed
 

src/platform_impl/android/keycodes.rs

@@ -108,6 +108,7 @@ pub fn to_physical_key(keycode: Keycode) -> PhysicalKey {
         Keycode::MediaStop => KeyCode::MediaStop,
         Keycode::MediaNext => KeyCode::MediaTrackNext,
         Keycode::MediaPrevious => KeyCode::MediaTrackPrevious,
+        Keycode::MediaEject => KeyCode::Eject,
 
         Keycode::Plus => KeyCode::Equal,
         Keycode::Minus => KeyCode::Minus,
@@ -130,7 +131,11 @@ pub fn to_physical_key(keycode: Keycode) -> PhysicalKey {
         // These are exactly the same
         Keycode::ScrollLock => KeyCode::ScrollLock,
 
+        Keycode::Eisu => KeyCode::Lang2,
+        Keycode::Muhenkan => KeyCode::NonConvert,
+        Keycode::Henkan => KeyCode::Convert,
         Keycode::Yen => KeyCode::IntlYen,
+        Keycode::Ro => KeyCode::IntlRo,
         Keycode::Kana => KeyCode::Lang1,
         Keycode::KatakanaHiragana => KeyCode::KanaMode,
 
@@ -153,6 +158,14 @@ pub fn to_physical_key(keycode: Keycode) -> PhysicalKey {
         Keycode::Sleep => KeyCode::Sleep, // what about SoftSleep?
         Keycode::Wakeup => KeyCode::WakeUp,
 
+        Keycode::CapsLock => KeyCode::CapsLock,
+        Keycode::Help => KeyCode::Help,
+
+        Keycode::Back => KeyCode::BrowserBack,
+        Keycode::Forward => KeyCode::BrowserForward,
+        Keycode::Refresh => KeyCode::BrowserRefresh,
+        Keycode::Search => KeyCode::BrowserSearch,
+
         keycode => return PhysicalKey::Unidentified(NativeKeyCode::Android(keycode.into())),
     })
 }