Fix Glide IllegalArgumentException in MauiCustomTarget.clear() for destroyed activities (#29780)

## Problem

Random crashes occurring on Android devices with the error:
```
java.lang.IllegalArgumentException: You cannot start a load for a destroyed activity
	at com.bumptech.glide.manager.RequestManagerRetriever.assertNotDestroyed(RequestManagerRetriever.java:236)
	at com.bumptech.glide.manager.RequestManagerRetriever.get(RequestManagerRetriever.java:110)
	at com.bumptech.glide.manager.RequestManagerRetriever.get(RequestManagerRetriever.java:92)
	at com.bumptech.glide.Glide.with(Glide.java:545)
	at com.microsoft.maui.glide.MauiCustomTarget.lambda$clear$0$com-microsoft-maui-glide-MauiCustomTarget(MauiCustomTarget.java:88)
```

This happens when Glide attempts to clear image targets using a Context
whose underlying Activity has been destroyed.

## Solution

Added defensive context destruction check in `MauiCustomTarget.clear()`
before calling `Glide.with(context).clear(this)`.

**Key Changes:**

1. **Added private context lifecycle validation methods to
MauiCustomTarget:**
- `isContextDestroyed()` - Checks if context/activity is destroyed or
finishing
- `getActivity()` - Safely extracts Activity from Context (handles
ContextWrapper chains)

2. **Protected MauiCustomTarget.clear() operation:**
- Added context check before calling `Glide.with(context).clear(this)`
- Includes verbose logging when the clear operation is skipped due to
destroyed context

**Behavior:**
- When context is destroyed, `clear()` returns early without attempting
to call Glide
- Matches Glide's own validation logic: `activity.isFinishing() ||
activity.isDestroyed()`
- Logs a debug message when clear is skipped (if verbose logging is
enabled)

**Example of the fix:**
```java
private void clear() {
    post(() -> {
        if (isContextDestroyed(context)) {
            if (logger.isVerboseLoggable) {
                logger.v("clear() skipped - context destroyed: " + resourceLogIdentifier);
            }
            return;
        }
        Glide
            .with(context)
            .clear(this);
    });
}
```

This is a surgical, minimal fix that targets the specific crash location
identified in the stack trace while maintaining all existing
functionality.

Fixes #29699.

---

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: jfversluis <939291+jfversluis@users.noreply.github.com>
Co-authored-by: jonathanpeppers <840039+jonathanpeppers@users.noreply.github.com>

Author: 3 people

src/Core/AndroidNative/maui/src/main/java/com/microsoft/maui/glide/MauiCustomTarget.java

@@ -1,6 +1,8 @@
 package com.microsoft.maui.glide;
 
+import android.app.Activity;
 import android.content.Context;
+import android.content.ContextWrapper;
 import android.graphics.drawable.Drawable;
 import android.os.Handler;
 import android.os.Looper;
@@ -80,10 +82,40 @@ private void post(Runnable runnable) {
         handler.post(runnable);
     }
 
+    private static boolean isContextDestroyed(Context context) {
+        Activity activity = getActivity(context);
+        if (activity != null) {
+            if (activity.isFinishing() || activity.isDestroyed()) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private static Activity getActivity(Context context) {
+        if (context == null) {
+            return null;
+        }
+        if (context instanceof Activity) {
+            return (Activity) context;
+        }
+        if (context instanceof ContextWrapper) {
+            Context baseContext = ((ContextWrapper) context).getBaseContext();
+            return getActivity(baseContext);
+        }
+        return null;
+    }
+
     private void clear() {
         // TODO: it looks like no one is really disposing the result on C# side
         // we must fix it there to release the Glide cache entry properly
         post(() -> {
+            if (isContextDestroyed(context)) {
+                if (logger.isVerboseLoggable) {
+                    logger.v("clear() skipped - context destroyed: " + resourceLogIdentifier);
+                }
+                return;
+            }
             Glide
                 .with(context)
                 .clear(this);