Remove ANDROID_BUILD_TOP from intelliJ path variables.

The variable is not actually needed and it makes working with different
API levels a lot easier since everything now depends on $PROJECT_DIR$.

This change also makes the tests more robust by improving the way it
tries to find the SDK.

Change-Id: I3502ad4a0ba85fd88b497e47964fddb2a89e520c
diff --git a/tools/layoutlib/bridge/bridge.iml b/tools/layoutlib/bridge/bridge.iml
index 7553b59..0f96916 100644
--- a/tools/layoutlib/bridge/bridge.iml
+++ b/tools/layoutlib/bridge/bridge.iml
@@ -34,11 +34,11 @@
     <orderEntry type="module-library" scope="TEST">
       <library>
         <CLASSES>
-          <root url="jar://$ANDROID_BUILD_TOP$/prebuilts/misc/common/sdk-common/sdk-common.jar!/" />
+          <root url="jar://$MODULE_DIR$/../../../../../prebuilts/misc/common/sdk-common/sdk-common.jar!/" />
         </CLASSES>
         <JAVADOC />
         <SOURCES>
-          <root url="jar://$ANDROID_BUILD_TOP$/prebuilts/misc/common/sdk-common/sdk-common-sources.jar!/" />
+          <root url="jar://$MODULE_DIR$/../../../../../prebuilts/misc/common/sdk-common/sdk-common-sources.jar!/" />
         </SOURCES>
       </library>
     </orderEntry>