fix: Fixing the memory leak introduced in the DPoP flow

Author: pmathew92

auth0/src/main/java/com/auth0/android/dpop/DPoP.kt

@@ -22,7 +22,9 @@ public data class HeaderData(val authorizationHeader: String, val dpopProof: Str
  * Class for securing requests with DPoP (Demonstrating Proof of Possession) as described in
  * [RFC 9449](https://datatracker.ietf.org/doc/html/rfc9449).
  */
-public class DPoP(private val context: Context) {
+public class DPoP(context: Context) {
+
+    private val applicationContext: Context = context.applicationContext
 
     /**
      * Determines whether a DPoP proof should be generated for the given URL and parameters. The proof should
@@ -79,7 +81,7 @@ public class DPoP(private val context: Context) {
      */
     @Throws(DPoPException::class)
     internal fun generateKeyPair() {
-        DPoPUtil.generateKeyPair(context)
+        DPoPUtil.generateKeyPair(applicationContext)
     }
 
     /**

auth0/src/test/java/com/auth0/android/authentication/AuthenticationAPIClientTest.kt

@@ -76,6 +76,7 @@ public class AuthenticationAPIClientTest {
         mockAPI = AuthenticationAPIMockServer()
         mockKeyStore = mock()
         mockContext = mock()
+        whenever(mockContext.applicationContext).thenReturn(mockContext)
         val auth0 = auth0
         client = AuthenticationAPIClient(auth0)
         gson = GsonBuilder().serializeNulls().create()

auth0/src/test/java/com/auth0/android/dpop/DPoPTest.kt

@@ -47,6 +47,8 @@ public class DPoPTest {
         mockResponse = mock()
         mockKeyStore = mock()
         mockResponseBody = mock()
+
+        whenever(mockContext.applicationContext).thenReturn(mockContext)
         dPoP = DPoP(mockContext)
 
         DPoP._auth0Nonce = null

auth0/src/test/java/com/auth0/android/provider/WebAuthProviderTest.kt

@@ -95,6 +95,7 @@ public class WebAuthProviderTest {
 
         mockKeyStore = mock()
         mockContext = mock()
+        Mockito.`when`(mockContext.applicationContext).thenReturn(mockContext)
 
         DPoPUtil.keyStore = mockKeyStore