Can't open file inside WEB-INF directory inside of Cloud Endpoints (GAE Java)

[MicroR via StackOverflow]

I'm trying to get a reference to a file in Cloud Endpoints (GAE Java) but I keep getting this error server side:

com.me.myapp.backend.utilities.Logger logError: [04/04/2016 6:32:24 PM] Exception in GoogleCloudStorageHelper.
java.security.AccessControlException: access denied ("java.io.FilePermission" "/WEB-INF/service-account-credentials.p12" "read")
    at java.security.AccessControlContext.checkPermission(AccessControlContext.java:382)
    at java.security.AccessController.checkPermission(AccessController.java:572)
    at java.lang.SecurityManager.checkPermission(SecurityManager.java:549)
    at com.google.apphosting.runtime.security.CustomSecurityManager.checkPermission(CustomSecurityManager.java:55)
    at java.lang.SecurityManager.checkRead(SecurityManager.java:888)
    at java.io.FileInputStream.<init>(FileInputStream.java:156)
    at java.io.FileInputStream.<init>(FileInputStream.java:117)
    at com.me.myapp.backend.gcs.GoogleCloudStorageHelper.loadKeyFromPkcs12(GoogleCloudStorageHelper.java:67)

What I am trying to do is reference a .p12 file I have in my project to get a private key in order to create a signed URL to a Cloud Storage object:

final String SERVICE_ACCOUNT_PKCS12_FILE_PATH = "/WEB-INF/service-account-credentials.p12";
PrivateKey key = loadKeyFromPkcs12(SERVICE_ACCOUNT_PKCS12_FILE_PATH, "notasecret".toCharArray());

private static PrivateKey loadKeyFromPkcs12(String filename, char[] password) throws Exception {
        FileInputStream fis = new FileInputStream(filename);
        KeyStore ks = KeyStore.getInstance("PKCS12");
        ks.load(fis, password);
        return (PrivateKey) ks.getKey("privatekey", password);
    }

But I guess I do not have permission to access my file? I read elsewhere that maybe I do not have the path correct to the file - if so, what should the path be..? My file is in the WEB-INF directory.

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