AAPT2: Clean up tests a bit

Since the latest gtest has fixed support for
explicit bool operators, remvoe AAPT_ASSERT_* and AAPT_EXPECT_*.

Also switch to use NotNull() matchers, which are more legible.

Test: make aapt2_tests
Change-Id: Idce199ca9d567d70f7aae275fee15e04bb914c9e
diff --git a/tools/aapt2/compile/IdAssigner_test.cpp b/tools/aapt2/compile/IdAssigner_test.cpp
index d465091..5cff004 100644
--- a/tools/aapt2/compile/IdAssigner_test.cpp
+++ b/tools/aapt2/compile/IdAssigner_test.cpp
@@ -64,12 +64,12 @@
   // Expect to fill in the gaps between 0x0101XXXX and 0x0104XXXX.
 
   maybe_result = table->FindResource(test::ParseNameOrDie("android:dimen/two"));
-  AAPT_ASSERT_TRUE(maybe_result);
+  ASSERT_TRUE(maybe_result);
   EXPECT_EQ(make_value<uint8_t>(2), maybe_result.value().type->id);
 
   maybe_result =
       table->FindResource(test::ParseNameOrDie("android:integer/three"));
-  AAPT_ASSERT_TRUE(maybe_result);
+  ASSERT_TRUE(maybe_result);
   EXPECT_EQ(make_value<uint8_t>(3), maybe_result.value().type->id);
 
   // Expect to bypass the reserved 0x0104XXXX IDs and use the next 0x0105XXXX
@@ -77,17 +77,17 @@
 
   maybe_result =
       table->FindResource(test::ParseNameOrDie("android:string/five"));
-  AAPT_ASSERT_TRUE(maybe_result);
+  ASSERT_TRUE(maybe_result);
   EXPECT_EQ(make_value<uint8_t>(5), maybe_result.value().type->id);
 
   // Expect to fill in the gaps between 0x01040000 and 0x01040006.
 
   maybe_result = table->FindResource(test::ParseNameOrDie("android:attr/bar"));
-  AAPT_ASSERT_TRUE(maybe_result);
+  ASSERT_TRUE(maybe_result);
   EXPECT_EQ(make_value<uint16_t>(1), maybe_result.value().entry->id);
 
   maybe_result = table->FindResource(test::ParseNameOrDie("android:attr/baz"));
-  AAPT_ASSERT_TRUE(maybe_result);
+  ASSERT_TRUE(maybe_result);
   EXPECT_EQ(make_value<uint16_t>(2), maybe_result.value().entry->id);
 }
 
@@ -121,7 +121,7 @@
   ASSERT_TRUE(VerifyIds(table.get()));
   Maybe<ResourceTable::SearchResult> result =
       table->FindResource(test::ParseNameOrDie("android:attr/foo"));
-  AAPT_ASSERT_TRUE(result);
+  ASSERT_TRUE(result);
 
   const ResourceTable::SearchResult& search_result = result.value();
   EXPECT_EQ(make_value<uint8_t>(0x01), search_result.package->id);