swift: fix naming of trailer removal functions (#266)
swift: fix naming of trailer removal functions (#266)

Updating these names to match up with the Swift header modification functions, as well as the Kotlin interfaces.

Signed-off-by: Michael Rebello <d207f8179edebd36c6ff33f7db1973b360eda8cd@lyft.com>

envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile,envoyproxy/envoy-mobile