Move Volley from frameworks/volley to external/volley.

Bug: 35896431
Change-Id: I4a3d38c1ce483f644900ea22ff8037f24c55a91e

default.xml

@@ -320,6 +320,7 @@
   <project path="external/vboot_reference" name="platform/external/vboot_reference" groups="vboot,pdk-fs" />
   <project path="external/vixl" name="platform/external/vixl" groups="pdk" />
   <project path="external/vogar" name="platform/external/vogar" groups="pdk" />
+  <project path="external/volley" name="platform/external/volley" groups="pdk" />
   <project path="external/vulkan-validation-layers" name="platform/external/vulkan-validation-layers" groups="pdk" />
   <project path="external/webp" name="platform/external/webp" groups="pdk,qcom_msm8x26" />
   <project path="external/webrtc" name="platform/external/webrtc" groups="pdk" />
@@ -362,7 +363,6 @@
   <project path="frameworks/rs" name="platform/frameworks/rs" groups="pdk" />
   <project path="frameworks/support" name="platform/frameworks/support" groups="pdk-cw-fs,pdk-fs" />
   <project path="frameworks/data-binding" name="platform/frameworks/data-binding" groups="pdk-cw-fs,pdk-fs" />
-  <project path="frameworks/volley" name="platform/frameworks/volley" groups="pdk-cw-fs,pdk-fs" />
   <project path="frameworks/webview" name="platform/frameworks/webview" groups="pdk-cw-fs,pdk-fs" />
   <project path="frameworks/wilhelm" name="platform/frameworks/wilhelm" groups="pdk-cw-fs,pdk-fs" />
   <project path="hardware/akm" name="platform/hardware/akm" group="pdk" />