message: test(http): Add + to encoding test
  Changes the existing test for query parameter encoding to include the +
  symbol and its expected encoding to %2B.
  PR Close
diff: @@ -178,8 +178,8 @@ import {HttpParams} from '@angular/common/http/src/params';
  it('should encode parameters', () => {
  const body = new HttpParams({fromString: 'a=standard_chars'});
  expect(body.toString()).toEqual('a=standard_chars');
  - const body2 = new HttpParams({fromString: 'a=1 2 3&b=mail@test&c=3_^[]$&d=eq=1'});
  - expect(body2.toString()).toEqual('a=1%202%203&b=mail@test&c=3_%5E%5B%5D$&d=eq=1');
  + const body2 = new HttpParams({fromString: 'a=1 2 3&b=mail@test&c=3_^[]$&d=eq=1&e=1+1'});
  + expect(body2.toString()).toEqual('a=1%202%203&b=mail@test&c=3_%5E%5B%5D$&d=eq=1&e=1%2B1');
  });
  });
  