RDKEMW-5550 - NetworkManager Plugin Release - 0.21.0 (#930)

Reason for change: Upgrade to new release - 0.21.0 with following Bug fixes

Fixed WiFi On/Off toggling failure
Fixed the bug in IPAddress availability check upon wake-up
Removed the SetPrimartInterface method
Added input param validation for Ping and Stun methods

Author: gururaajar

conf/include/generic-pkgrev.inc

@@ -284,7 +284,7 @@ PV:pn-memcr = "1.0.2"
 PR:pn-memcr = "r0"
 PACKAGE_ARCH:pn-memcr = "${MIDDLEWARE_ARCH}"
 
-PV:pn-networkmanager-plugin = "0.20.0"
+PV:pn-networkmanager-plugin = "0.21.0"
 PR:pn-networkmanager-plugin = "r0"
 PACKAGE_ARCH:pn-networkmanager-plugin = "${MIDDLEWARE_ARCH}"