Fixed blank space after closing keyboard

[Sharcoux]

Description

Fixes a blank space left at the bottom of the WebView after the Android keyboard is dismissed when resizeOnFullScreen is enabled.

Changes in Keyboard.java:

• Reset the content view height to MATCH_PARENT when the IME is hidden, instead of -1
• Register a single OnApplyWindowInsetsListener on the content view (only when resizeOnFullScreen is true) and remove duplicate resize calls from the insets animation callback
• Add edge-to-edge aware usable height calculation on Android 15+, accounting for system bar insets based on Capacitor’s adjustMarginsForEdgeToEdge config

Change Type

• Fix
• Feature
• Refactor
• Breaking Change
• Documentation
• Other (CI, chores, etc.)

Rationale / Problems Fixed

When resizeOnFullScreen is enabled, the WebView is manually resized while the keyboard is open. After the keyboard is dismissed, the content view height was reset to -1, which does not reliably restore the layout on all devices — a blank gap can remain at the bottom of the screen.

Upstream #60 improved this by resetting height when the keyboard hides without animation, but -1 still leaves residual layout issues in some cases. This PR resets to MATCH_PARENT explicitly and consolidates resize handling into the window insets listener so hide/show transitions are handled consistently.

Also adds edge-to-edge adjustments for Android 15+ so usable height is computed correctly when system bar insets apply.

Tests or Reproductions

Tested on Android with resizeOnFullScreen: true:

1. Focus an input field to open the keyboard → WebView resizes correctly
2. Dismiss the keyboard (back button, tap outside, or programmatic hide) → WebView fills the screen with no blank gap at the bottom
3. Repeat open/close several times → layout stays stable
4. Tested with edge-to-edge enabled on Android 15+

Screenshots / Media

N/A — layout issue best observed interactively on device/emulator.

Platforms Affected

• Android
• iOS
• Web

Notes / Comments

• Builds on top of upstream fix(android): reset WebView height when keyboard hides without animation #60; does not revert its null-safe insets handling or SystemBars delegation
• Resize logic is only active when resizeOnFullScreen is enabled in plugin config
• When the SystemBars plugin is present, resize remains delegated to SystemBars as upstream already does