fix: migrate deprecated edge-to-edge APIs for Android 15

[Agamya-Samuel]

Description (required)

This PR migrates the app away from deprecated Android 15 APIs related to edge-to-edge display. Google Play has flagged these deprecated APIs that need to be updated before targeting Android 15:

• Add enableEdgeToEdge() to LoginActivity for proper edge-to-edge setup
• Remove redundant WindowCompat.setDecorFitsSystemWindows() call
• Update DarkAppTheme with transparent status/navigation bar colors

Fixes #6275

Tests performed (required)

Tested ProdDebug and BetaDebug on Medium Phone emulator (Android Virtual Device) with API level 36 (Android 15).

Screenshots (for UI changes only)

None - This is a behind-the-scenes API migration with no visible UI changes. The edge-to-edge display behavior remains the same.

[RitikaPahwa4444]

Update DarkAppTheme with transparent status/navigation bar colors

None - This is a behind-the-scenes API migration with no visible UI changes. The edge-to-edge display behavior remains the same.

@Agamya-Samuel will it be visible in dark mode?

[Kota-Jagadeesh]

Hi @Agamya-Samuel, I'm getting this build error - would you mind checking? Thanks!

Unresolved reference. None of the following candidates is applicable because of receiver type mismatch: 
public fun ComponentActivity.enableEdgeToEdge(statusBarStyle: SystemBarStyle = ..., navigationBarStyle: SystemBarStyle = ...): Unit defined in androidx.activity

[Agamya-Samuel]

Update DarkAppTheme with transparent status/navigation bar colors

None - This is a behind-the-scenes API migration with no visible UI changes. The edge-to-edge display behavior remains the same.

@Agamya-Samuel will it be visible in dark mode?

I'll check and let you know.

[Agamya-Samuel]

Hi @Agamya-Samuel, I'm getting this build error - would you mind checking? Thanks!

Unresolved reference. None of the following candidates is applicable because of receiver type mismatch: 
public fun ComponentActivity.enableEdgeToEdge(statusBarStyle: SystemBarStyle = ..., navigationBarStyle: SystemBarStyle = ...): Unit defined in androidx.activity

Can you please share the steps, what led to this error.

[Kota-Jagadeesh]

Can you please share the steps, what led to this error.

Tried to build --> compilation fails at LoginActivity.kt line ~81 with the above error

[Agamya-Samuel]

Can you please share the steps, what led to this error.

Tried to build --> compilation fails at LoginActivity.kt line ~81 with the above error

Ok I will look into this

[RitikaPahwa4444]

@Agamya-Samuel please feel free to mark the PR as draft until you find a fix 🙌🏻