Fix leaking activity context

[ploboda]

Despite clear instructions in Superwall SDK's docs to pass the application context to the Superwall.configure() method, given no type safe distinction between activity context and application context, it's possible to mistakenly pass an activity context, like in the example app. That can lead to memory leaks, as the SDK holds a reference to the context for its whole lifecycle that is longer than lifecycle of an Activity.
It can also cause app crashes, for example when initialising JavaScriptSandbox after the activity is finished.
Steps to reproduce the crash in Example application:

• Disable Paywalls preloading, e.g. in Superwall options
• Finish MainActivity when navigating to HomeActivity
• Run Example app
• Click "Log in" and "Launch Feature" to initialise JavaScriptSandbox after MainActivity is finished.

Logs:

FATAL EXCEPTION: ExpressionEvaluator
Process: com.superwall.superapp, PID: 21254
java.lang.RuntimeException: bindService() returned false Intent { cmp=com.google.android.webview/org.chromium.android_webview.js_sandbox.service.JsSandboxService0 }
	at androidx.javascriptengine.JavaScriptSandbox.lambda$bindToServiceWithCallback$1(JavaScriptSandbox.java:423)
	at androidx.javascriptengine.JavaScriptSandbox$$ExternalSyntheticLambda0.attachCompleter(Unknown Source:6)
	at androidx.concurrent.futures.CallbackToFutureAdapter.getFuture(CallbackToFutureAdapter.java:102)
	at androidx.javascriptengine.JavaScriptSandbox.bindToServiceWithCallback(JavaScriptSandbox.java:410)
	at androidx.javascriptengine.JavaScriptSandbox.createConnectedInstanceAsync(JavaScriptSandbox.java:358)
	at com.superwall.sdk.paywall.presentation.rule_logic.expression_evaluator.ExpressionEvaluator$1.invokeSuspend(ExpressionEvaluator.kt:54)

To avoid errors, the SDK can precautionary get application context from the context passed into Superwall.configure() method.
Given that, the SDK requirements could get relaxed to allow initialisation with activity context.