Make the benchmark actually measure the benchmark build, and record what the phone will and will not answer

The run was installing app-debug.apk the whole time, which would have published debug numbers as the release-like ones. AGP 9's com.android.test extension has no testBuildType and no targetVariant - it exposes only targetProjectPath - and the target variant is matched by name against the test module's own build types. So the module now declares a benchmark build type, and inherits the debug signing config with initWith: a declared type starts unsigned, and an unsigned test APK fails with INSTALL_PARSE_FAILED_NO_CERTIFICATES. The command is now :benchmark:connectedBenchmarkAndroidTest, and -PbenchmarkBuild is gone from the workflow; the conditional testBuildType it used to set in :app only ever moved the unit-test variant, which is why it made :app:testDebugUnitTest disappear.

The storage grant also had to move into the test. The rule uninstalls and reinstalls the app before measuring, an uninstall clears app-ops, and appops set from inside the test does not work even under adoptShellPermissionIdentity - the command fails to stderr, which executeShellCommand does not return, and appops get still reads No operations. What does work is tapping what a user taps: Grant full access, then the platform consent, then back out of the all-files page. grantStorageAccess does that in setupBlock, unmeasured, and it is what turned three failing tests into three passing ones.

The search test now waits for the app bar's search action in setup instead of looking it up immediately inside the measured block, where it came back null one frame after a thousand rows rendered.

What the device answers: coldStart passes at 560.6 ms P50 (a third measurement of the 532 ms figure), scroll passes but reports only frameCount and no frame durations at all, open dies on INSTALL_FAILED_USER_RESTRICTED because the rule's reinstall wants a human, and search still cannot see the search action. PERFORMANCE.md now states that per benchmark instead of the earlier guess, names the four switches that make an unattended run possible, and says that three of the four numbers need a device that installs unattended and reports frame timing.

docs/CODE_MAP.md

@@ -2,7 +2,7 @@
 
 Generated from the source by `tools/make-code-map.py` - do not edit by hand. Regenerate it after a change (`python3 tools/make-code-map.py`); `--check` exits non-zero when this file is stale.
 
-77 source files, 12660 lines - 33 test files, 386 tests. The behaviour index at the end lists every test name, and in this project a test name is a sentence about what the app does, so it doubles as the specification.
+77 source files, 12704 lines - 33 test files, 386 tests. The behaviour index at the end lists every test name, and in this project a test name is a sentence about what the app does, so it doubles as the specification.
 
 Start at `AGENTS.md`. What is done, and why: `docs/ROADMAP.md` and `CHANGELOG.md`. What was verified by hand rather than by a test: `docs/EDGE_CASE_TESTING.md`.
 
@@ -170,7 +170,7 @@ The macrobenchmark test APK: four measurements over a fixture folder, run on a d
 
 | file | lines | what it holds | tests |
 |---|---|---|---|
-| `BrowserBenchmark.kt` | 168 | The four numbers docs/PERFORMANCE.md promises, measured on a benchmark build of the app. BrowserBenchmark, Fixture | - |
+| `BrowserBenchmark.kt` | 212 | The four numbers docs/PERFORMANCE.md promises, measured on a benchmark build of the app. BrowserBenchmark, Fixture | - |
 
 ## Behaviour index