WebAnalyticsExtAppController sonar issues

- Rename this local variable to match the regular expression
- Make this anonymous inner class a lambda.
- Immediately return this expression instead of assigning it to
the temporary variable "response".
- Move the "" string literal on the left side of this string comparison.
- Replace the type specification in this constructor call
with the diamond operator ("<>").

Issue-ID: PORTAL-648
Change-Id: I1666d94dccbbe8aa835ea9a443a9973a245353f4
Signed-off-by: Dominik Mizyn <d.mizyn@samsung.com>