Use soong_zip and zip2zip to make dist faster

soong_zip parallelizes the compression when creating a zip file, which
makes these packaging steps far shorter.

zip2zip skips the decompression and recompression during the -img- file
creation.

For an aosp_arm64-eng aosp/master build:

target_files.zip: 92s to 60s
symbols.zip: 147s to 7s
img.zip: 64s to 0.5s

There's still room to parallelize the image compression during
target_files.zip (add_img_to_target_files step takes most of the time)

Change-Id: I7b6a91e4a7dbeda2e49ca936b10181cff2f973d7
diff --git a/core/config.mk b/core/config.mk
index 4ad212f..4f4b742 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -472,6 +472,9 @@
 DX := $(HOST_OUT_EXECUTABLES)/dx
 MAINDEXCLASSES := $(HOST_OUT_EXECUTABLES)/mainDexClasses
 
+SOONG_ZIP := $(SOONG_HOST_OUT_EXECUTABLES)/soong_zip
+ZIP2ZIP := $(SOONG_HOST_OUT_EXECUTABLES)/zip2zip
+
 # Always use prebuilts for ckati and makeparallel
 prebuilt_build_tools := prebuilts/build-tools
 prebuilt_build_tools_bin := $(prebuilt_build_tools)/$(HOST_PREBUILT_TAG)/bin