Fixed standalone emulator when ANDROID_BUILD_TOP is present

With ANDROID_BUILD_TOP android-configure.sh searches for prebuilt
directories later used for locating ccache.  At this moment, ccache
is located in different location between AOSP and internal tree.
Beside, "prebuilt" is gone in internal tree.

Change-Id: Ib14b8c91c9f8026605617f2abf94c3bee9ddadb6
diff --git a/android-configure.sh b/android-configure.sh
index beb7427..01fc2c4 100755
--- a/android-configure.sh
+++ b/android-configure.sh
@@ -196,15 +196,9 @@
     # use ccache if USE_CCACHE is defined and the corresponding
     # binary is available.
     #
-    # note: located in PREBUILT/ccache/ccache in the new tree layout
-    #       located in PREBUILT/ccache in the old one
-    #
     if [ -n "$USE_CCACHE" ] ; then
         CCACHE="$ANDROID_PREBUILT/ccache/ccache$EXE"
         if [ ! -f $CCACHE ] ; then
-            CCACHE="$ANDROID_PREBUILT/ccache$EXE"
-        fi
-        if [ ! -f $CCACHE ] ; then
             CCACHE="$ANDROID_PREBUILTS/ccache/ccache$EXE"
         fi
         if [ -f $CCACHE ] ; then
diff --git a/android/build/common.sh b/android/build/common.sh
index c7235ae..e3e190b 100644
--- a/android/build/common.sh
+++ b/android/build/common.sh
@@ -499,10 +499,10 @@
 {
     # locate prebuilt directory
     ANDROID_PREBUILT_HOST_TAG=$OS
-    ANDROID_PREBUILT=$ANDROID_TOP/prebuilt/$ANDROID_PREBUILT_HOST_TAG
-    ANDROID_PREBUILTS=$ANDROID_TOP/prebuilts/misc/$ANDROID_PREBUILT_HOST_TAG
+    ANDROID_PREBUILT=$ANDROID_TOP/prebuilt/$ANDROID_PREBUILT_HOST_TAG  # AOSP still has it
+    ANDROID_PREBUILTS=$ANDROID_TOP/prebuilts/misc/$ANDROID_PREBUILT_HOST_TAG # AOSP does't have it yet
     if [ ! -d $ANDROID_PREBUILT ] ; then
-        # this can happen when building on x86_64
+        # this can happen when building on x86_64, or in AOSP
         case $OS in
             linux-x86_64)
                 ANDROID_PREBUILT_HOST_TAG=linux-x86
@@ -511,8 +511,7 @@
             *)
         esac
         if [ ! -d $ANDROID_PREBUILT ] ; then
-            echo "Can't find the prebuilt directory $ANDROID_PREBUILT in Android build"
-            exit 1
+            ANDROID_PREBUILT=
         fi
     fi
     if [ ! -d $ANDROID_PREBUILTS ] ; then
@@ -525,8 +524,7 @@
             *)
         esac
         if [ ! -d $ANDROID_PREBUILTS ] ; then
-            echo "Can't find the prebuilts directory $ANDROID_PREBUILTS in Android build"
-            exit 1
+            ANDROID_PREBUILTS=
         fi
     fi
     log "Prebuilt   : ANDROID_PREBUILT=$ANDROID_PREBUILT"