android: Upgrade Hardware.java APIs for API 26+/23+/24+ compatibility - #3380

Updates Hardware.java to use modern Android APIs, replacing several
deprecated calls that produce lint warnings on API 26+ targets.

Changes

Vibration (vibrate)

• Use VibrationEffect.createOneShot() on API 26+
• Fall back to the legacy Vibrator.vibrate(long) on older devices

Network detection (checkNetwork)

• Use ConnectivityManager.getActiveNetwork() + NetworkCapabilities
  on API 23+ instead of the deprecated getActiveNetworkInfo()
• Detects Wi-Fi, cellular, and Ethernet transports explicitly

Network listener (registerNetworkCheck)

• Register a ConnectivityManager.NetworkCallback on API 24+
  instead of the deprecated CONNECTIVITY_ACTION broadcast
• Falls back to the broadcast receiver on older devices

Context / View access

• Expose context and view as public (were package-private)
• Add getContext() helper that falls back to PythonActivity.mActivity
• Add getView() helper that falls back to the activity's decor view

WiFi scanning (enableWifiScanner)

• Obtain WifiManager via getApplicationContext() (avoids memory leak
  with non-application contexts)
• Wrap getScanResults() in a SecurityException catch block
  (required permission ACCESS_FINE_LOCATION on API 29+)

Misc

• Replace String += concatenation loops with StringBuilder
• Remove redundant (float[]) casts on readSensor() return values
• Add sSensor == null guard in changeStatus() for devices that lack
  a particular sensor type

Testing

• Verified no behavioural regression on a device running API 36.
• Legacy code (API < 23/24/26) remain unchanged via SDK version checks.
• Same Hardware.java file is being used for ksproject toolchain. (All of these are tested and improved maintaining backward compatibility.)