test: Add UI and logic to evaluate boolean flags (#305)

## Summary
Introduced a text field and button in CustomerApiButtons to input and
evaluate a boolean flag key. Added evaluateBooleanFlag method in
ViewModel to fetch the flag value and display the result using a Toast
message.

## How did you test this change?
No tests needed

## Are there any deployment considerations?
No

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Adds UI and logic to input a flag key and evaluate a boolean flag via
LDClient, showing the result in a Toast.
> 
> - **Android UI (Compose)**:
> - In `CustomerApiButtons`, add `OutlinedTextField` for `flagKey` input
and a button to evaluate it via `viewModel.evaluateBooleanFlag`.
> - **ViewModel**:
> - Add `evaluateBooleanFlag(flagKey)` that uses
`LDClient.boolVariation` and displays the result with a `Toast`;
validates non-empty key.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
a3d020f. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: agrognetti

e2e/android/app/src/main/java/com/example/androidobservability/MainActivity.kt

@@ -18,7 +18,6 @@ import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material3.Button
-import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
@@ -197,7 +196,6 @@ private fun MaskingButtons() {
     val context = LocalContext.current
 
 
-
     // Three-column layout: Name | XML | Compose
     // User Form
     Row(
@@ -322,6 +320,7 @@ private fun MaskingButtons() {
 private fun CustomerApiButtons(viewModel: ViewModel) {
     var customLogText by remember { mutableStateOf("") }
     var customSpanText by remember { mutableStateOf("") }
+    var flagKey by remember { mutableStateOf("") }
     var customContextKey by remember { mutableStateOf("") }
 
     Text(
@@ -386,6 +385,23 @@ private fun CustomerApiButtons(viewModel: ViewModel) {
 
     Spacer(modifier = Modifier.height(16.dp))
 
+    OutlinedTextField(
+        value = flagKey,
+        onValueChange = { flagKey = it },
+        label = { Text("Flag key") },
+        modifier = Modifier.padding(8.dp)
+    )
+    Button(
+        onClick = {
+            viewModel.evaluateBooleanFlag(flagKey)
+        },
+        modifier = Modifier.padding(8.dp)
+    ) {
+        Text("Evaluate boolean flag")
+    }
+
+    Spacer(modifier = Modifier.height(16.dp))
+
     OutlinedTextField(
         value = customContextKey,
         onValueChange = { customContextKey = it },

e2e/android/app/src/main/java/com/example/androidobservability/ViewModel.kt

@@ -2,6 +2,7 @@ package com.example.androidobservability
 
 import android.app.Application
 import android.content.Intent
+import android.widget.Toast
 import androidx.core.content.ContextCompat
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.viewModelScope
@@ -124,6 +125,15 @@ class ViewModel(application: Application) : AndroidViewModel(application) {
         LDClient.get().identify(context)
     }
 
+    fun evaluateBooleanFlag(flagKey: String) {
+        if (flagKey.isNotEmpty()) {
+            val result = LDClient.get().boolVariation(flagKey, false)
+            Toast.makeText(getApplication(), "Flag $flagKey: $result", Toast.LENGTH_SHORT).show()
+        } else {
+            Toast.makeText(getApplication(), "Flag key cannot be empty", Toast.LENGTH_SHORT).show()
+        }
+    }
+
     fun startForegroundService() {
         val intent = Intent(getApplication(), ObservabilityForegroundService::class.java)
         ContextCompat.startForegroundService(getApplication(), intent)