Use trimmed API key (#1768)

### Description
I noticed that trusted entitlements may fail if passing an API key with
extra whitespaces. This is because it's part of the data we are
verifying and the backend uses the trimmed version so there is a
mismatch. This trims the API key we use in the SDK, so it matches what
the backend uses in those cases. Any real API key shouldn't contain any
whitespaces so I think it should be fine but lmk what you think

purchases/src/main/kotlin/com/revenuecat/purchases/PurchasesConfiguration.kt

@@ -37,7 +37,7 @@ open class PurchasesConfiguration(builder: Builder) {
 
     init {
         this.context = builder.context
-        this.apiKey = builder.apiKey
+        this.apiKey = builder.apiKey.trim()
         this.appUserID = builder.appUserID
         this.purchasesAreCompletedBy = builder.purchasesAreCompletedBy
         this.service = builder.service

purchases/src/test/java/com/revenuecat/purchases/PurchasesConfigurationTest.kt

@@ -110,4 +110,10 @@ class PurchasesConfigurationTest {
         val purchasesConfiguration = builder.dangerousSettings(dangerousSettings).build()
         assertThat(purchasesConfiguration.dangerousSettings).isEqualTo(dangerousSettings)
     }
+
+    @Test
+    fun `PurchasesConfiguration trims api key`() {
+        val purchasesConfiguration = PurchasesConfiguration.Builder(context, "  test-api-key  ").build()
+        assertThat(purchasesConfiguration.apiKey).isEqualTo("test-api-key")
+    }
 }

purchases/src/test/java/com/revenuecat/purchases/PurchasesFactoryTest.kt

@@ -89,11 +89,9 @@ class PurchasesFactoryTest {
     }
 
     private fun createConfiguration(testApiKey: String = "fakeApiKey"): PurchasesConfiguration {
-        return mockk<PurchasesConfiguration>().apply {
-            every { context } returns contextMock
-            every { apiKey } returns testApiKey
-            every { appUserID } returns "appUserID"
-            every { store } returns Store.PLAY_STORE
-        }
+        return PurchasesConfiguration.Builder(contextMock, testApiKey)
+            .appUserID("appUserID")
+            .store(Store.PLAY_STORE)
+            .build()
     }
 }